How ChartFI models your money

You are financially independent in the first year your after-tax portfolio covers that year's FI Number, which already nets out your Social Security, pension and other ongoing income. After-tax means tax-deferred balances count after your plan's own average federal and state tax on its tax-deferred withdrawals and Roth conversions (and any pre-59½ penalty), and any outstanding deficit is subtracted first. It also has to be a year you could leave full-time work in: a paid wind-down you entered carries on, at its pay, from that year until your full retirement age. If leaving then would run your money short, or leave less in hand at any point than a year of spending (or what the rest of your life needs, if that's less), FI is the first later year where it wouldn't. Two numbers fall out of that and appear throughout the app:

• FI Number = whichever is lower: that year's recurring spending, less the Social Security, pension and annuity or rent income paid that year, ÷ your safe withdrawal rate (SWR), with a pension, annuity or rent counted at SWR ÷ (SWR + inflation) of itself (about 57% at 4% and 3%) because it doesn't rise with prices; or your spending for each year until your Social Security, pension or other ongoing income starts (and until any loan you carry is paid off, if that is later), less what that income pays in each, and less the wind-down pay you'd earn in each of those years if you left full-time work then, plus your spending after that, net of that income, ÷ SWR. At a 4% SWR, $100k of spending needs $2.5M while no benefits are paid, and $1.5M once $40k a year of Social Security is paying. Five years before benefits start, though, the years in between cost $500k, so that year's FI Number is $500k plus $1.5M: $2.0M. One-time purchases and money you are saving don't count as spending here.
• FI Year = the first calendar year your projected after-tax portfolio reaches that year's FI Number and, if you left full-time work that year, keeping any paid wind-down until your full retirement age, your money would last your lifetime with at least a year of spending in hand, or what the rest of your life needs if that's less.
• Funded from <age> = Your plan covers your spending in every projected year from your retirement age, though your portfolio reaches that year's FI Number only later, often when Social Security starts and the FI Number falls. Your savings carry the years in between. If you would not reach that age, the plan says how long it covers you instead.
• Rule year = On a plan funded from its retirement age, the FI Year, named for your withdrawal rate (at a 4% rate, the 4%-rule year): the year your portfolio reaches the cushion that rate asks for. The ring shows it beside “Funded from”. It is a safety margin arriving, not the year you can stop working.

Spending is organized around five life phases — Working, Wind-down, Early retirement, Retired and Downsized — because the budget differs in each. The last three require you to have actually retired: turning 65 is a health-coverage fact, not a work fact, so a plan that works to 70 keeps contributing and keeps its working budget until then. Downsized needs both triggers — retired and past your downsize year.

Tax planning segments on different boundaries, because the tax rules change at ages the budget does not care about: the 10% early-withdrawal penalty before 59½, the ACA gap between retiring and Medicare, Medicare from 65, and RMDs from 73, or 75 if you were born in 1960 or later. The Strategy Optimizer sizes a separate Roth-conversion ceiling for each of three stretches: before 59½, from 59½ to 65, and from 65 until RMDs begin.

Taxes are where a FIRE plan is won or lost, so this is where ChartFI spends most of its effort. Each projection year computes taxes from your actual income sources and account types, not a flat effective rate:

The constants ship for the current tax year and are the same for every plan — they are not a per-plan setting. Like any model of the tax code, they are an approximation that improves as the rules are updated.

Each return you enter is a compound annual rate: the rate your money grows at, year after year. Your projection grows every account at exactly that rate, so it shows the typical (median) path: while you are saving, about as many simulated futures end up above it as below. Real markets deliver good and bad years in an unlucky order (“sequence-of-returns risk”). The Monte Carlo analysis runs hundreds of alternate lifetimes for your exact plan, each with the same typical growth and the ups and downs around it, and reports the share in which your plan always met its spending needs (the success rate), the range of portfolio outcomes (the fan chart), and how much your FI date moves with luck.

A plan that never runs short at a steady return is not the same as a plan that can survive a bad run of years. Once you are living on your savings, losses early on are hard to make back, so the typical simulated future can fall behind the projection after you stop working, and a plan the projection shows fully funded can still run short in a fair share of simulated futures. That gap is the risk the success rate measures.

On top of the fan chart you can overlay named historical scenario lines — a deterministic replay of your exact plan through real cohorts such as the Great Depression (1929), the 1966 stagflation retiree, the 2000 dot-com-and-GFC lost decade, and the 1982 bull market — each using that era's actual returns and inflation. The underlying return data comes from public sources (Damodaran / NYU Stern for stocks, bonds, cash and inflation; Nareit for REITs).

The honest limit hasn't moved: every mode still rests on a finite return history and on assumptions you can only estimate, so read the success rate as a stress-test of your plan's resilience, not a probability of the future. The right use is to push returns, volatility, inflation, or withdrawal rate to a pessimistic case and watch how far the FI Year slips.

The calculation engine is checked for consistency across more than 100 household scenarios — every field of every projection year is compared with the last reviewed run, so a code change that moves any number is caught before it ships. On top of that, every projected year is kept as a ledger: each dollar that comes in, goes out, is taxed or moves between accounts is recorded once, from where to where, and the year's money has to close: every account ends at its start plus what moved in and out, and nothing is left over. A year that didn't close would be shown to you as an error, never as a figure.

Separately, the core tax rules are checked against cases worked out by hand from the IRS's own tables and the tax code — the brackets, required minimum distributions, the net investment income tax and how Social Security is taxed — and each state's tax figures against that state's own published sources. Where a state hasn't published this year's figures yet, the limits below say so.

What that buys you is a model that computes what it says it computes, the same way every time. It does not, and cannot, promise the market will cooperate.

A model is a set of choices. Below is what ChartFI does not offer, and the places it deliberately simplifies a rule instead of modeling it exactly: what it does instead, which way that moves your numbers, and who it affects.

• No accuracy percentages or guarantees. We don't publish an “X% accurate” figure, because no honest projection can. A projection is an estimate from stated assumptions.
• No account aggregation. ChartFI doesn't link to your bank or brokerage; you enter balances and, once a year, real year-end numbers in Plan vs Actual. That's a deliberate privacy trade-off.

Outside what ChartFI models in beta

During the beta, ChartFI is built and checked for single filers, married couples filing jointly, two unmarried adults sharing a household, and a single parent filing as Head of Household — living in one state, with pay from a job and the account types you can add today. A plan outside that still runs, and tells you which of these it hits.

• Married filing separately. ChartFI files two returns for you and applies the separate-return rules it knows — among them the loss of the ACA premium tax credit and the separate Medicare surcharge brackets — but those rules have had less checking than a joint return's. Your real tax, credits and surcharges could be higher or lower than the plan shows.
• Filing separately in a community-property state. In Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington and Wisconsin, ChartFI splits a couple's wages and investment income evenly across the two returns. The exceptions to that split are listed under Federal tax, and others it doesn't model at all, so your tax could come out higher or lower.
• A married couple filing as Single or Head of Household. If you set a married couple to Single or Head of Household for some years on Tax Strategy, ChartFI reads those years as two returns, one particular way — described under Federal tax. Your situation may not be that one.
• Moving to another state. ChartFI taxes the whole year of a planned move in your new state. Real part-year returns split the year between the two states, each with its own rules, so the state tax in the year you move could be higher or lower than the plan shows. Every other year is taxed by the state you live in.
• Self-employment or 1099 income. ChartFI taxes all pay as wages from a job. It doesn't charge self-employment tax — about twice the payroll tax an employee pays — or give the deduction for half of it or the qualified business income deduction, and it uses an employee's 401(k) limits, not the larger Solo 401(k) or SEP limits. For most self-employed people that understates federal tax; for a higher-earning business with employees or property, the missing qualified business income deduction can outweigh it.

Federal tax

• A stock fund's dividends are all treated as qualified. An account's income yield — its dividends and interest — is taxed every year as it's paid. In a taxable account, ChartFI treats all of a stock or stock fund's dividends as qualified, so the federal return taxes them at the 0%, 15% or 20% capital-gains rates. Interest, bond and cash yields, and REIT distributions are taxed as ordinary income. Your state taxes all of it as ordinary income, as most states do. Some funds pay part of their dividends as non-qualified, mostly international and high-turnover funds. If you hold those, your real federal tax is a little higher than the plan shows. Your 1099-DIV shows how much of a fund's dividends were qualified.
• Capital gains use average cost basis, and start from the cost basis you enter. Selling shares from a taxable account to fund spending realizes capital gain on the appreciation above your cost basis, at the account's average — there are no individual tax lots, so specific-lot selection and tax-loss harvesting aren't modeled, and every gain is treated as long-term. Each account keeps its own average, so a withdrawal realizes the gain or loss of the account it sells from, and an account you entered at a loss (a cost basis above 100%) does not net against another account's gain. If you don't enter a cost basis for an account, the plan assumes the balance you typed is entirely basis and taxes only the growth it projects from there, which understates the tax on holdings you have owned for a long time.
• A few states' rules for a capital loss are approximated. A sale at a loss nets against that year's gains on your state return, and the $3,000 deduction and carryforward follow the federal return where your state does. Not modeled: Alabama's deduction of a year's whole net loss, Massachusetts' $2,000 cap against interest and dividends only, Pennsylvania's bar on netting one spouse's loss against the other's gain, and Washington's netting for its gains tax.
• A second sale from the same property reuses its whole cost basis. When you plan the sale of real estate or another holding you can't draw from, and don't give that sale a cost basis, the plan uses the one you entered for the holding. The first sale from it is priced exactly. The plan doesn't keep track of how much of that basis the first sale used, so a later sale from the same holding counts the whole basis again, showing less gain — and less tax — than you would owe. Giving each sale its own cost basis avoids this.
• A planned sale can reach the accounts the plan keeps together with its own. The plan keeps some accounts as one balance: all your Roth accounts, all your HSAs, all your emergency funds, each person's IRAs, and each person's 401(k), 403(b) and 457(b) plans. A planned sale from one of them can sell up to what that group holds, so if it asks for more than its own account has, the plan can show more money from it than you could raise. A sale never takes another person's 401(k) or IRA money, and never sells from a shared balance before its own account starts, and the plan's checks say when a sale asks for more than there is to sell.
• A planned sale, and the sale of your home, happen at the start of the year. The plan sells at what the holding was worth when the year began, so the money sold earns nothing that year: none of the year's growth on what you sell (the gain on the sale is figured without it), none of its dividends or interest, and the proceeds the year doesn't spend reach their account at the end of the year. When a sale leaves you no property, the plan treats you as owning none for all of that year, so it deducts no mortgage interest that year, though a loan the sale doesn't pay off is still paid. Your home's own mortgage is paid off at what it owed when the year began, with no payments or interest that year, and a home you buy in its place grows for the whole year. So in the year of a sale your figures can be off either way: less growth and more tax than a sale later in the year would bring, but no mortgage cost that year on the home you sell and a full year's growth on the one you buy.
• All pay is taxed as an employee's wages. Social Security and Medicare tax is charged at the employee's rates on all pay. Self-employment pay, such as consulting after you retire, really owes self-employment tax of about 14.1%, so for that pay the plan understates payroll tax by roughly half. In the other direction, a health premium taken out of your paycheck before tax stays in payroll wages here, which overstates payroll tax by up to 7.65% of it. An HSA contribution marked as a payroll deduction does come out of your payroll wages, but your IRA's pay limit and the 401(k) Roth catch-up's wage test still count your pay before it, which can matter only when your pay barely covers your IRA or sits just over that test's threshold.
• A married couple's extra Medicare tax is shared by paycheck. Filing jointly, you owe the extra 0.9% Medicare tax on your combined pay over $250,000, and the tax code doesn't say whose it is. The plan gives each of you the share your own paycheck withholds (pay over $200,000 from your employer), or splits it by pay if neither paycheck withholds any. Your household's payroll tax is exact; one of your paystubs can show a different split, which your return settles when you file.
• Future federal tax law is today's, carried forward. Brackets, the standard deduction, contribution limits and the other figures the tax code adjusts for inflation are carried forward at your inflation assumption (for the brackets and the standard deduction, less a fixed 0.2 percentage points a year for the slower index the law uses); real years will differ. The Social Security wage base, which the law ties to average wages, moves with prices instead, so a high earner far in the future pays slightly less payroll tax here than the law would charge. The ACA subsidy's contribution percentages, the federal poverty line behind it (the figures for the 48 contiguous states, used for Alaska and Hawaii too, where the real line is higher) and Medicare's IRMAA surcharge amounts stay at this year's values. No future change in the law is anticipated. Later years can therefore be off in either direction, most of all for marketplace coverage and for incomes in the IRMAA range.
• Two itemized-deduction figures are settled before the year's Roth conversion. If you itemize, the plan measures the income test on the state-and-local-tax deduction cap without the year's Roth conversion, which the law includes. In a year with a large conversion the plan's cap can therefore come out larger than the law's, and that year's tax slightly low. The same test takes off your planned 401(k), HSA and IRA contributions in full, even in a year your cash cannot fund all of them, so in such a year the cap can come out larger in the same way. For a couple filing two returns, which return claims the itemized deductions is chosen on income before the conversion, and at the year's final income the other choice can occasionally cost a little less.
• Your state income tax counts toward itemizing, one year behind. When you itemize, the plan deducts the state income tax it worked out for the year before, plus any property and other taxes you entered, up to the federal limit. The first year uses that year's own state tax. So the deduction can be a little high or low in the first year, and in the year after a big change in income or a move to another state. If you file two returns, each deducts its own share, and in your first year filing separately last year's joint bill is split evenly. Six states that start from your federal deduction (Colorado, Idaho, Missouri, Montana, New Mexico and Utah) take the state income tax back out, as their own forms do; Iowa and North Dakota leave it in. The plan never itemizes on the state return itself, so state tax is a little high if you would. Missouri, for one, lets itemizers add payroll taxes. And if you file separately in one of those six states, the plan picks itemizing or the standard deduction by federal tax alone, which can cost more state tax than it saves. Washington's tax on large capital gains is deducted here as a state income tax. Washington calls it an excise, and the IRS hasn't said whether it can be deducted. If it can't, federal tax is a little too low in the year after a Washington household pays it.
• Charitable gifts from an IRA are modeled only alongside, and up to, required distributions. The law lets you give straight from an IRA, tax-free, from 70½. The plan models a qualified charitable distribution only in a year you also take a required minimum distribution, so if you give from an IRA before your RMDs begin, your real tax in those years is lower than the plan shows. It also caps each person's gift at their own RMD, though the law allows each person far more (over $100,000 a year) whatever the RMD. If you give more than your RMD from an IRA, your real tax is lower than the plan shows. An account whose kind you haven't set counts as a workplace plan, so no gift is made from it. Withdrawals and conversions come out of a person's IRA and workplace plans in proportion to what each holds, so if you would draw your 401(k) first, your real gifts could be larger and your tax lower. After a death, the plan treats the whole balance the survivor inherits as an inherited IRA, which a gift can come from, and lets it give from the age the person who died would have been, as it does their required distributions. The law allows no such gift to a survivor who leaves an inherited 401(k) in the plan, or who is younger than 70½, so for them the real tax is higher than the plan shows.
• Ages are counted in whole calendar years. The plan knows the year you were born, not your birthday, so a rule that starts at an age — the end of the early-withdrawal penalty at 59½, Medicare and the extra standard deduction at 65, the start of RMDs — applies for whole calendar years rather than from your birthday. The year a rule takes effect can be a year earlier or later than it is for you.
• A married couple set to Single or Head of Household files two returns, read one way. On Tax Strategy you can set a married couple's filing status to Single or Head of Household for some years. ChartFI reads Single as divorced or legally separated by the end of the year, so you each file your own Single return. It reads Head of Household as living apart for the last six months of the year: the spouse who claims the children files Head of Household, and the other spouse, still married, files separately — at the separate-filer rates, with no ACA premium tax credit, and with no standard deduction if the Head of Household return itemizes. If that other spouse would qualify as Head of Household too, or you mean a different situation, the plan overstates your tax. In Washington, two Single returns each take the capital-gains deduction. A legally separated couple still shares one there, so for them the plan understates that tax.
• In those years, income isn't split under community-property law. In a community-property state, a married couple filing separately normally reports half of the couple's wages and investment income on each return, and ChartFI does that for a couple filing separately. In a year you set to Single or Head of Household it attributes income to whoever earned it instead, as for a separated or divorced couple. If community-property rules still applied to part of your income that year, your real tax could be higher or lower than the plan shows.
• A Traditional IRA deduction in a community-property state uses each return's own income. When a married couple in a community-property state files separately, each spouse deducts their own IRA contribution on their own return, as the IRS requires. The income test that can limit that deduction for someone covered by a workplace plan is read on each return's income after the community-property split. If your tax preparer reads that test on your own earnings instead, the deductible amount — and your tax — could come out higher or lower than the plan shows.
• Roth conversion targets are sized before the year's own capital gains are known. When ChartFI sizes a year's Roth conversion to stay under a tax bracket, the 3.8% investment income tax threshold or a Medicare surcharge tier, it sets aside room for the capital gains you realized the year before, less any capital loss you carry into the year, as its estimate of this year's. When this year's gains turn out larger, the conversion can land a little over the target; when they are smaller, it can stop a little short. The ACA subsidy limit is the exception: it uses the year's own gains.

State and local tax

• Some kinds of income follow your federal return on your state return. Where we have not checked a state's own rule for a kind of income, such as a pension, a retirement account withdrawal, a Roth conversion or interest, we treat it the way your federal return does. A state that taxes that income differently can make your real state tax higher or lower than the plan shows.
• Interest on US Treasuries is taxed by your state. Federal law exempts interest on Treasury bills, notes and bonds from state income tax, but nothing in the plan says which of your holdings are Treasuries, so their interest is taxed like any other. If you hold Treasuries or a Treasury fund in a taxable account and live in a state with an income tax, your real state tax is lower than the plan shows.
• Some states' retirement-income exclusions aren't applied. New York (up to $20,000 a person from 59½), Louisiana (from 65), Oklahoma, Arkansas, Alabama (from 65), Wisconsin (from 67) and Delaware (a pension before 60) each let retirees keep some retirement income out of state tax (in New York and Wisconsin that includes money converted to a Roth IRA); the plan applies none of these. Michigan's subtraction is applied: pensions, and from your own 59½ retirement-account withdrawals and Roth conversions, up to one limit per return, then dividends, interest and gains for someone born before 1946. It counts a whole 401(k) withdrawal, where Michigan counts only the part from required or employer contributions (tax too low), and it holds a public pension to the limit even for someone born before 1946, who can subtract it all (tax too high). It reads a surviving spouse's own birth year, where Michigan lets a widow or widower who has not remarried use the older spouse's (tax too high). Kentucky's exclusion is applied to each person's pension and retirement-account withdrawals, but not to an annuity you enter as other ongoing income. Georgia's (from 62) and Delaware's (from 60) exclusions are applied, including to dividends, interest and gains, and so are the age-65 deductions in South Carolina, Virginia and Montana. Montana's is taken only from income other than long-term gains, so a Montana retiree living mostly on gains pays a little too much. New Jersey's pension exclusion from 62 is applied too, up to its $150,000 income limit, and so is the rule that lets any unused part cover dividends, interest and gains when you earn $3,000 or less from work. Three New Jersey rules aren't: the exclusion for someone under 62 who is disabled, the $6,000 extra exclusion for a household that can never collect Social Security, and treating an annuity you enter as other ongoing income as a pension (it only reaches the unused part). Minnesota's subtraction for people 65 and older is applied, reduced by the part of your Social Security that isn't federally taxed and by half your income over its limit, but not its version for someone under 65 who is disabled. West Virginia's $8,000 deduction from 65 is applied to each person's own income, less their taxable Social Security (for a couple, split by each spouse's benefit), but not for someone under 65 who is disabled or the surviving spouse of someone who was 65. Colorado's subtraction goes by each person's own age: from 55, up to $20,000 ($24,000 from 65) of pension, retirement-account withdrawals and taxable Social Security together, all the taxable Social Security from 65 (from 55 at an income up to $75,000, $95,000 for a couple), and under 55 up to $20,000 of money paid because of a death; not an annuity you enter as other ongoing income, or military retirement under 55. If you're retired in one of the other states, your real state tax is likely lower than the plan shows.
• Pennsylvania's exemption for pensions starts at 59½ here. Pennsylvania doesn't tax a pension, or a withdrawal from a workplace plan, once you've retired under that plan's own age and service rules, however old you are, and it never taxes military retirement pay. The plan doesn't know your plan's rules, so it exempts them only from 59½, the age Pennsylvania uses for an IRA. If your pension starts earlier, at a set age such as 45 or 50, or you draw from a workplace plan before 59½ after retiring from it, the plan shows Pennsylvania tax on that money until you turn 59½, so your real state tax is likely lower than the plan shows. A withdrawal paid because the account's owner died is exempt at any age, as Pennsylvania's law has it.
• Some state rules for retirement money you inherit are applied only in part. Iowa leaves retirement money paid because of a death out of state tax when the person who died would have been 55 or older that year, and South Carolina gives a surviving spouse a separate deduction on that money, figured at the age the person who died would have been. ChartFI applies both to a surviving spouse. Iowa's rule can also cover an unmarried partner, or your children or other heirs after the last death, when they can show an “insurable interest”, and the plan doesn't apply it to them. South Carolina's deduction stops in the plan once the survivor reaches the age at which the plan treats the inherited account as rolled into their own, and so does Pennsylvania's exemption for that money, which for an unmarried partner (who can't roll it over) comes too soon when that age is below 59½. In those cases your real state tax is likely lower than the plan shows.
• Minnesota's Social Security subtraction isn't applied. Minnesota lets you subtract some or all of your taxable Social Security, depending on your income. The plan doesn't, so it taxes all of the benefit your federal return taxes. If this applies to you, your real state tax is likely lower than the plan shows.
• Your state tax follows the federal adjustments, with a few gaps. The plan subtracts pre-tax 401(k), Traditional IRA and HSA contributions and qualified charitable distributions from state income the way federal income does, and adds them back where a state taxes them. Pennsylvania taxes 401(k) contributions. Pennsylvania, New Jersey and Massachusetts don't allow the Traditional IRA deduction. California and New Jersey tax HSA contributions and the interest and dividends an HSA earns each year, as the plan does. New Jersey keeps a charitable distribution in income; that reading of New Jersey's rule is an estimate. Some gaps remain. California and New Jersey also tax gains made inside an HSA, which the plan doesn't model, so their tax can be too low. Pennsylvania, New Jersey and Massachusetts don't tax contributions you already paid state tax on when you withdraw them, and the plan taxes the whole withdrawal, which is also too high. New Jersey and Massachusetts treat a Roth conversion the same way, and the plan taxes the whole conversion there. New Jersey taxes 403(b) and 457(b) contributions, but the plan can't tell them from a 401(k), so for those savers New Jersey tax is too low. Maryland's county tax is worked out before 401(k) and HSA contributions come off, and Pennsylvania's local earned income tax before HSA contributions come off, which can make both too high. On a joint Georgia return, up to $5,000 of a 62-or-older spouse's wages counts toward their retirement exclusion even when part of those wages went into their 401(k), as long as the other spouse still has wages, which can make Georgia tax slightly too low. Mississippi taxes a withdrawal taken early (before 59½, with the federal penalty), but the plan applies Mississippi's retirement exemption to every withdrawal, so for those savers Mississippi tax is too low. Colorado's pension subtraction likewise leaves out an early withdrawal the federal return penalises, and the plan subtracts it from 55, so Colorado tax is too low for those savers too.
• Your state's deductions and exemptions are applied, with a few gaps. The plan takes your state's own standard deduction, personal and dependent exemptions and exemption credits, including the extra amounts at 65 and the way they shrink at higher incomes — or the federal deduction, if your state uses that one. A few things it can't apply, because it doesn't ask about them: extra amounts for being blind, disabled or a veteran, and relief that only very low incomes get. States' own child tax credits and earned-income credits aren't applied, and neither is Massachusetts's deduction of up to $2,000 of payroll tax per worker. Alabama, Missouri and Oregon also let you deduct some of the federal income tax you paid, and the plan doesn't yet. All of these make state tax too high. In the other direction, the plan gives every dependent a state's amount for a child, so where an older dependent gets less — in Arizona, North Carolina and Indiana — state tax can be a little too low. South Carolina's extra exemption for a child under 6 isn't applied, which makes tax there a little too high. Montana taxes long-term gains on a separate schedule, and the plan takes the deduction off your other income only, so a Montana household living mostly on gains is charged too much. Where a state reduces an amount in very small steps as income rises, as Alabama and California do, the plan reduces it smoothly instead, which is off by a few dollars at most. Ohio's joint filing credit is applied when each spouse has pay, a pension or retirement-account withdrawals of their own. Rent doesn't count for that credit, and the plan holds an annuity and rent in one figure, so if one spouse's only income of their own is an annuity, the credit is left out and Ohio tax can be up to $650 too high. Ohio's retirement income credit (up to $200) and its $50 credit for filers 65 and over, both for incomes under $100,000, aren't applied either. Nor are Colorado's TABOR refunds, the sales-tax refund and any temporary rate cut, which the state sets each year from its surplus, so Colorado tax can be a little too high. Maryland's subtraction of up to $1,200 for a couple who both have income is applied, but it measures each spouse's income before their own HSA contribution, so where one spouse earns less than $1,200 and puts some of it in an HSA, Maryland tax can be a few dollars too low. Virginia's spouse tax adjustment, up to $259 for a couple who both have income, is applied too; it splits your taxable income between you in proportion to your incomes, where Virginia's worksheet splits your deductions one by one, so it can be off either way, by less than $259.
• If you're married and file separately, the children go on Person 1's return. A state's exemptions and credits for children go on the return that claims them. When a married couple files separately, the plan has no setting for which spouse that is, so it uses Person 1. If your state taxes your two returns at different rates, your state tax would be a little higher or lower with the children on Person 2's return instead.
• Most local income taxes aren't modeled. City, county and school-district income taxes — Indiana's county taxes, New York City's, Portland's, Michigan's city taxes, Ohio's school-district taxes and Iowa's school surtax among them — are left out, so if you owe one, your real tax is higher than the plan shows. Pennsylvania's local earned-income tax and Maryland's county tax are included, each at one statewide average rate rather than your own locality's, so they can be off in either direction; Maryland's is applied to pay and other ongoing income but not to retirement-account withdrawals or capital gains, which the county tax also reaches.
• State tax law stays as it is this year. Your state's brackets, deductions and exemptions are held at this year's amounts in every future year, even where the state's own law adjusts them for inflation, and changes a state has already enacted for later years — such as Georgia's, Indiana's and Mississippi's scheduled rate cuts, or Rhode Island's surtax on income over $1,000,000 from 2027 — aren't applied. For most states that makes later years' state tax too high; for Rhode Island's highest earners, too low.
• Where a state hasn't published this year's figures, its latest ones are used. California's tax brackets, Washington's capital-gains deduction, Rhode Island's Social Security income limit and Montana's age-65 subtraction are last year's published figures, and Vermont's brackets are the ones the state calls preliminary. The standard deductions, exemptions and credits of Arkansas, California, D.C. and Vermont, Oregon's head-of-household deduction, Idaho's zero-rate band and South Carolina's dependent exemption are last year's too, and so are Michigan's limits on its retirement subtraction. Louisiana's standard deduction is the state's own estimate, and Maryland's for joint returns is the lower of the two amounts its rule allows. These figures usually rise each year, so state tax there tends to come out slightly high.
• A few states' single and head-of-household brackets are approximated. Where the plan doesn't yet carry a state's own schedule for single filers (Minnesota, New Mexico, North Dakota and Vermont) or heads of household (California, Minnesota, Nebraska, North Dakota and Vermont), that return is taxed on the wider married-joint brackets, so its state tax comes out too low. For a married couple filing separately, Washington's higher capital-gains rate starts at $1,000,000 of each return's own gain, where the spouses may have to share one threshold, which can understate it too. And Missouri couples, who figure each spouse's tax separately, are taxed on one table for their combined income, which makes their state tax too high. Delaware lets a married couple put each spouse's income in its own column of one return, which usually costs a two-earner couple less; the plan files one joint return, so their Delaware tax is likely too high.

Social Security and health coverage

• No benefits from a former spouse's record. Social Security can pay a divorced person up to half of an ex's full retirement benefit while the ex is alive, and a survivor benefit after they die, when the marriage lasted ten years or more and you haven't remarried. ChartFI models neither: each person's benefit comes from their own earnings record, and spousal and survivor top-ups are modeled only for a couple who are currently married. If a long marriage of yours ended, your real benefit may be higher than this plan shows.
• The ACA premium tax credit is estimated first and trued up a year later. Each year's credit is first estimated from the year before's income, as the marketplace does when you re-enroll, and the difference from what that year's own income allows is settled the following year, as it is on your tax return. So the lifetime total is exact and the error is timing only: a year's credit can read high one year and show as repaid the next, or the other way round. This applies only if you buy marketplace coverage and have marked a Budget line as the unsubsidised premium.
• A workplace-plan saver's IRA deduction does not lower their taxable Social Security. If you collect Social Security, are covered by a retirement plan at work and deduct a Traditional IRA contribution, the plan works out how much of your benefit is taxable before that deduction rather than after it. In a year your benefit is only partly taxable, up to 85 cents of each dollar you deduct stays taxable, so the plan can overstate your federal tax. An IRA deduction for someone not covered at work is counted in full.
• Who your marketplace premium covers is read from who still works. A premium you enter for the years after retiring is counted for each adult under 65 who has stopped full-time work or is unpaid, and is credited to them. A partner still working full time is taken to be covered by their employer, and so are the children their tax return claims. If that partner or those children are on your marketplace plan instead, the plan understates both the premium and the credit for those years. If a partner has stopped working but keeps employer coverage, it overstates both.
• HSA contributions stop in the year you enroll in Medicare. Each of you is taken to enroll in Medicare, all parts at once, in the year you reach the Medicare age you set for each of you: 65 unless you set a later one, as you might while a high-deductible plan at work still covers you. Once you're on Medicare you can no longer put money into an HSA, so from that year the plan puts nothing into yours and takes no deduction for it; the money a Budget line had going there stays in your cash instead. It counts whole years, so it errs either way: at 65 it counts none of the months before your birthday; after 65, Part A starts up to six months before you apply (not before 65), claim or not, and it counts those in the year before. A Social Security claim starts Part A too: the plan says so but keeps your age. Disability Medicare before 65 is not modelled.

Accounts, withdrawals and estates

• Annuity and rental income is one flat, fully taxed amount. Other ongoing income — an annuity or rent — is a single yearly figure that doesn't grow, so rent that rises with inflation is understated in later years. All of it is taxed as ordinary income: the part of an annuity payment that returns your own money isn't excluded, which overstates the tax. And rent is treated as passive, so the 3.8% net investment income tax applies above its threshold even for a real-estate professional, who would not owe it.
• Early Roth withdrawals are treated generously. Before 59½, Roth contributions come out tax- and penalty-free, but converted money withdrawn within five years owes a 10% penalty, and earnings owe tax and the penalty. The plan tracks the conversions it makes, but it treats the Roth balance you start with as all contributions, draws earnings last (though ahead of a conversion made the same year), starts no five-year clock for a conversion made after 59½, and never penalizes a Roth holding sold by a planned sale. If you draw Roth money early, your real tax and penalty can be higher than the plan shows.
• Before 59½, extra money drawn early is set aside when your order would spend it first. If you draw from a 401(k) or IRA before 59½, the plan can draw a little more than a year needs. When that extra would go somewhere your withdrawal order spends after your 401(k) or IRA, and the plan is converting that year, it converts the extra to Roth instead, with no penalty. If you set a bracket to fill, it always sets the extra aside, because filling a bracket draws your other accounts before any 401(k) or IRA money past that bracket. Otherwise it sets the extra aside, after the 10% penalty, because your order would draw it again before your 401(k) or IRA. Converting that money too could still owe less, since it would only be spent later, but converted money is locked up for five years. Your real penalty can be lower than the plan shows.
• Before 59½, a year short of cash converts past its ceiling. With early withdrawals off, a Roth conversion is how the plan reaches your 401(k) or IRA before 59½. If a year that converts still can't pay its bills from the money it can reach, the plan converts more than your bracket cap, MAGI target or IRMAA cap (or the NIIT or ACA limit) allows, and spends the extra that year. It pays the tax and the 10% penalty on it, until the year is paid for or the account is empty. If you would hold your ceiling instead, your money may not last as long as the plan shows.
• The plan counts your emergency fund as money it can spend. When other accounts run low, or a working year's cash falls short, the plan draws the emergency fund like any other account. If you keep that money for emergencies, your plan may run short sooner than it shows.
• Money the plan draws from your HSA is treated as spent on medical costs. Your HSA has its own place in the withdrawal order, and when the plan draws it, the money comes out free of tax and penalty. A real HSA withdrawal is tax-free only when it pays medical costs; spent on anything else it is taxed as income, and before 65 it also owes a 20% penalty. So if the plan spends your HSA on other things, your tax can be higher than it shows.
• A partner you are not married to keeps your HSA untaxed. A spouse who inherits an HSA can keep it as their own HSA, and anyone else owes income tax on all of it in the year of death; the estate figures charge your heirs that tax. But for two partners who are not married, when the one who holds an HSA dies first, the plan lets the other keep it as an HSA, so their tax can be higher than it shows.
• Your heirs are taxed on the whole HSA they inherit. An heir can subtract the medical bills of the person who died that they pay within a year of the death. The plan does not know those bills, so what your heirs keep after tax can be higher than it shows.
• Real estate and other alternative assets are drawn a piece at a time. When the withdrawal order reaches them, the plan takes exactly what the year needs, as if part of a rental or a private fund could be sold on its own, and it charges no cost of selling. A real sale is usually all or nothing and costs money, so the cash these assets can raise in a year can be less than the plan shows.
• Accounts of the same kind grow at one blended rate, set at the start. Your 401(k)s and Traditional IRAs grow together at one rate, as do your Roth accounts, and so on. That rate is the average of their returns, weighted by what each holds when the plan starts, and it stays the same in every later year. If none of them holds money at the start, each is weighted by what you plan to contribute to it before any lump sum you've dated arrives or, if you contribute to none of them, by the balance you entered. So a lump sum you've dated to arrive later grows at the rate of the money already there, and money the plan moves in on its own, such as a Roth conversion, doesn't change the mix. A re-baselined plan starts from its original plan's mix and keeps its draw order while its accounts are the same. A balance you record above or below the planned one moves that account's weight in proportion, so money you moved between two accounts moves the rate toward the one that gained it.
• Money with no account of its kind grows at a standard rate. When the plan sets spare cash aside and you have no brokerage or emergency fund to put it in, it holds that cash for you, earning a typical cash rate taxed as interest. Money for a 401(k) or IRA you haven't added grows at a typical stock-market rate. Neither is a return you entered: add the account, with its own return, and the plan uses that instead.
• After-tax 401(k) money grows with the rest of your 401(k). Money you put in the after-tax part of a 401(k) and haven't converted to Roth yet earns the same return as the rest of the 401(k), not a return of its own. Converting it the year it goes in, which the plan does unless you hold the conversion, makes this moot.
• Coast-FI counts your pay after an average tax share. To find the first year you could stop saving, the plan spends the pay you used to save and keeps banking any pension, annuity or Social Security left after your spending. It charges that pay a share of the year's income tax, by income, not the extra tax the pay adds. That share can be more or less than the extra, so your Coast-FI milestone can come out a little earlier or later than it should.
• The Rule of 55 is modeled per person, not per plan. Leaving a job in or after the year you turn 55 lets you withdraw from that employer's plan without the 10% penalty. The plan keeps one separation age per person and tracks the eligible money per person. A contribution counts toward it when it is paid into a plan the rule covers, and an employer match when you hold one; a sale comes out of your other money first. And the after-tax portfolio behind your FI Year still discounts that money for the penalty before 59½, which can put your FI Year later than it would be.
• 72(t) payments are not modeled. Before 59½ (or the access age you set), the plan draws your own 401(k) and IRA money without the 10% penalty only through the Rule of 55, for a workplace plan you have left, or through Roth conversions once they have seasoned for five years. If you allow early withdrawals, it can also draw that money by paying the penalty; otherwise it counts it as locked until then. (Money you inherit from a late spouse is open at any age.) A 72(t) schedule of substantially equal payments can reach your own money sooner without the penalty, though it commits you to fixed yearly payments for at least five years. So money the plan counts as locked, or draws at a penalty, may be reachable without one.
• Tax-deferred money is counted at one average tax rate. Your 401(k) and traditional IRA money counts after the average federal and state income tax your own plan pays on what it withdraws and converts to Roth. It's one rate for the whole plan, so it runs high in some years and low in others. It leaves out effects on health-insurance credits and Medicare premiums. A plan that withdraws almost nothing uses 22%. The 10% penalty before 59½ is added on top.
• The years before Social Security earn nothing in your FI Number. Until your Social Security, pension or other ongoing income starts (and, if a loan you carry ends after that, until its last payment), your FI Number counts each year's spending in full, less any benefit, pension or annuity or rent income already paid, and adds what the plan's safe withdrawal rate needs for the years after. It uses whichever is lower: that, or the safe-withdrawal-rate multiple of this year's need. The money you set aside for those years is assumed to grow only with inflation, so if you would stop working before you claim, your FI Number is likely a little higher than you need.
• A pension, annuity or rent counts in your FI Number as a fixed payment for life. Your FI Number subtracts the pension and the other ongoing income your plan pays each year. Where it multiplies your spending by your safe withdrawal rate's multiple, it counts that income at your withdrawal rate ÷ (that rate + inflation) of itself, about 57% at 4% and 3%: what a payment that never rises with prices is worth, the way your plan pays it. It does not count that the payment stops when its holder dies, or what a partner would go on needing after that, so if you hold a pension or annuity, your FI Number can be a little low; if your rent rises with prices, a little high.
• Two IRA rules are simplified in your favor. A backdoor Roth — a nondeductible IRA contribution converted to Roth — is taxed as if you held no other pre-tax IRA money; if you do, the IRS pro-rata rule makes part of the conversion taxable, and the plan warns you rather than computing it. And a defined-benefit pension doesn't count as workplace-plan coverage when the plan limits your Traditional IRA deduction, so someone covered only by a pension may see a deduction the law wouldn't allow. Both understate tax.
• Your employer match is the amount you enter. The plan pays it in full in any year you work and defer pay into a 401(k) or 457(b), pre-tax or Roth, and not at all in a year you defer nothing, and a warning names those years. After-tax 401(k) money alone earns none, and the match stops when you retire, on your own clock, so a partner who keeps working after the other retires keeps theirs. It doesn't model your employer's matching formula, so a year your contribution is too small to earn the whole match (including a year your cash covers only part of your lines) may show more match than your employer would pay, and a plan that matches after-tax money may show less.
• Roth conversions stop the year before RMDs begin. Converting after RMDs start is legal, but neither your plan nor the Strategy Optimizer converts from then on, so whatever converting later might do for your plan is not shown.
• After a death, the deceased owner's RMD schedule continues. A surviving spouse who rolls an IRA into their own takes RMDs on their own age. The plan keeps taking them on the age the deceased owner would have been, so where the survivor is younger, withdrawals and their tax start earlier and run larger than they would; where the survivor is older, the reverse.
• After a death, your life phases keep the calendar you planned. Your spending phases and the withdrawal order that goes with them change in the years your plan set, counted on the age of the person the timeline follows. If that person dies first, the survivor's years keep the same calendar, as if they had lived, except that the Medicare years start when they would have turned 65, not at a later Medicare age they never reached. A survivor who would downsize or spend differently on their own schedule may see different figures.
• No step-up in basis at the first death of a couple. When someone dies, the investments they own take a new cost basis at their value that day, erasing the gain, and in community-property states the survivor's half does too. The plan applies the step-up only at the last death, so after a first death it taxes gains that would really have been erased, overstating the survivor's capital-gains tax.
• A capital loss you enter is held half by each of you. A capital loss belongs to the person who realized it, and every loss the plan realizes from your accounts and Sale events is tracked for its owner. The unused loss you enter has no owner on the form, so for a couple the plan holds half for each of you. That matters in two places. In a year you file two returns (married filing separately, or two unmarried partners), each of you deducts your half within your own limit: up to $1,500 on a separate return, $3,000 on a single one. If the loss is really one person's, the plan uses it up faster than you could, so it shows less tax in those years and more later. And at a couple's first death the half held by the person who died ends: if most of the loss was the survivor's, the plan shows more tax afterwards than you would owe; if most was the other person's, less. A plan you re-baseline keeps each person's part of the loss its source plan carried, and if you change the figure on it, each keeps their share of the new one.
• Mortgage interest is deducted up to the $750,000 debt limit. The interest on a liability you type as a mortgage counts as an itemized deduction, on up to $750,000 of mortgage debt ($375,000 if you are married and file separately). The plan doesn't know when you took out the loan, so it holds every loan to that limit, also one from before December 16, 2017 that the law holds to $1,000,000: for such a loan the plan shows more tax than you would owe. It also treats every mortgage as debt that bought or built a home you hold; interest on a home-equity loan spent on something else isn't deductible, so for that loan the plan shows less tax than you would owe. Nor does it know whose name a loan is in or who pays it: if the two of you file separate returns, or are partners who aren't married and each file a return, each of you deducts half of every loan's interest, under your own return's limit. If only one of you has income of your own, you file one return between you, and it deducts all of the interest. If one of you alone owes the loan or pays more than half of it, your returns would split the interest differently, and a loan above one return's limit can then deduct more or less than the plan shows.
• Mortgage interest in your other itemized deductions counts twice. The plan deducts the interest on every liability typed as a mortgage, and adds the other itemized deductions you enter on top of it. If that figure already includes your mortgage interest, the plan counts it twice and shows less tax than you would owe.
• Student-loan interest is not deducted. You can deduct up to $2,500 a year of student-loan interest, less as your income rises, and none on a married person's separate return. The plan doesn't, so if you qualify it shows more tax than you would owe.
• Savings with no named owner are split by pay. In a year you file two returns, money the plan saves into no account you named (your leftover cash, an Income event's extra, an emergency-fund overflow) is split between you by pay, and the account that holds it decides whose return taxes its earnings. Social Security left after your spending follows the person paid it, counting other income as spent before pay. Your real split may differ, so either return's tax could be off.
• A partner with no income of their own files a return only if their account starts with money. If you aren't married, or a filing range has you file as single or head of household, and one of you has no pay, pension or benefit, the plan gives that partner a return of their own only when a Tax-Deferred, Taxable or Alt account in their name, or a joint one, holds money when the plan starts. An account dated to start in the plan's first year or later doesn't count. On a re-baselined plan, each account counts as it did when it first entered the plan: when the plan it came from started, or, for an account you added to the re-baselined plan, when that plan started. An account you rename there counts as one you added. The plan decides this once, so that partner keeps their return even after the account is empty, and on every plan re-baselined from it. Money that reaches their account later, from an event, a sale, your savings or your leftover cash, is taxed on the other partner's return. In real life the account's owner reports its earnings, so either return's tax could be off.
• A couple's home is taken to be owned jointly. When you sell your home, each owner can exclude up to $250,000 of the gain on their own return. The plan doesn't ask who owns your home, so for a couple it assumes you own it half each. In a year you file two returns (married filing separately, or two unmarried partners), each return reports half the gain against its own $250,000, up to $500,000 together. If only one of you owns the home, only that person can exclude $250,000, so the plan shows less tax on the sale than you would owe. Any gain above the exclusions is split between your two returns the way your other investment gains are.
• Estate and inheritance taxes are simplified. The federal estate-tax exclusion is carried forward with inflation, but state estate-tax exemptions stay at this year's amounts, which overstates state estate tax for a death far in the future. Lifetime gifts aren't modeled, which understates the tax, and neither are trusts, QTIP elections or charitable planning, which overstates it for a planned estate, nor where out-of-state property sits. States with an inheritance tax are named but not priced, because the plan doesn't know who your heirs are.
• In Kentucky, the estate's state income tax after the last death reads a little low. For the years after the last person in a plan dies, ChartFI leaves out the part of each year's state income tax that comes from tax-deferred withdrawals, because the tax your heirs pay on that money is counted separately. It works that part out as the withdrawals' share of the year's income. Kentucky lets the estate keep a set amount of retirement income out of tax, and that amount isn't counted as income in the share, so the share comes out too large and the estate's state income tax for those years too small.
• After the last death, the Projection chart and table show payments to your heirs. Your tax-deferred accounts pass to your heirs at the last death, and your estate figures, what your heirs receive and the tax on it, are worked out then. For the years after, that chart and table still show the estate. What remains of each year's required distribution, after the estate's own costs and tax, is shown leaving it as a payment to your heirs, so those balances fall. The free growth chart and the printed report leave this payment out.

Monte Carlo

• With a mix of investments, the typical simulated path runs a little above your projection. The Monte Carlo sets each investment's simulated returns so that, on its own, its typical path grows at the return you entered over 30 years. A mix that doesn't move together swings less than its parts, so while you save its typical path runs slightly above the projection and the success rate reads a little high; once you draw on savings, a bad early run can pull it well below. Over 5 years an investment's runs about 0.2 points a year above your rate on the normal model, 0.3 to 0.45 on the fat-tailed one, and on the historical one 1.7 above for stocks but up to 0.6 below for bonds and real estate. By 20 years all three are within about 0.1 point of it.
• Monte Carlo FI years skip the stop-work check. Your projection counts a year as FI only if leaving full-time work then would leave your money lasting your lifetime, with at least a year of spending in hand, or what the rest of your life needs if that's less. The Monte Carlo skips that check, which would roughly double a run, so its FI Years are the first years each simulated path reaches your FI Number. After a bad run of early returns some would fail the check: on the plans we test, up to about 1 path in 10.

The Strategy Optimizer

• It doesn't score every combination. To finish in reasonable time it narrows its search in stages, screening candidates and then refining the best of them, so on some plans a combination slightly better than the one it recommends can exist.
• For a household filing two returns, its survivor-aware (or RMD-aware) conversion target is one limit for both. The target is a yearly income limit that fills a tax bracket, and it is built on the standard deduction. Unmarried partners and married couples filing separately each convert up to that same limit on their own return. When one of the two returns itemizes, that return converts less than would fill its bracket. For a married couple filing separately, the other spouse has no standard deduction once one of them itemizes, so that return can convert past the bracket, by up to the standard deduction it doesn't get.
• For a household filing two returns, it estimates the state tax rate as if your income were on one return. To weigh converting now against paying later, the target estimates the state income tax rate on the next dollar. For a household filing two returns it works that rate out on your combined income with a joint return's brackets, which comes out right when your two incomes are about equal. When they differ a lot, the rate it uses can be too high or too low. In New York, near the income where the state starts taking back the benefit of its lower brackets, it can be off by several points.
• For a couple, it reads an age-based state exclusion at one of your ages. Some states exclude retirement income from tax once you reach a certain age, each spouse on their own income. When it estimates the state tax rate on the next converted dollar, the conversion target uses the age of whichever of you has more in tax-deferred accounts, since most of that dollar is theirs. If only one of you has reached the state's age, the rate it uses can be too high or too low, so it can convert a little more or less than it should. Which of you was entered first doesn't change it.
• It values what your plan ends with as your heirs would receive it. To compare strategies, it counts the money left at the end after tax: every tax-deferred dollar as if your heirs pay 24% on it, the rate your estate figures assume; gains you haven't sold yet as untaxed, as their cost basis steps up at death; and the earnings in a 401(k)'s after-tax sub-account, and an HSA left over, at the same 24%, the sub-account's after-tax contributions untaxed. Your heirs may pay more or less than 24%, so it can lean either way between converting to Roth now and leaving money tax-deferred.

What-if answers

• Budget's “What if you spent less?” answers are approximate. To answer in one run, it lowers a phase's monthly total directly instead of changing your individual lines, so a line's own end year doesn't apply in that run. “Every phase” takes the same monthly amount off each phase your plan reaches, and a phase that spends less than that is set to zero. The FI year and the year the plan runs short that it reports are for that simplified plan; to see the exact effect, change the lines themselves.
• Retirement-age levers move one adult's age. On a couple's plan, the Strategy Optimizer and the retirement-age what-ifs move the retirement age of the adult your plan's timeline follows, with their part-time window, which keeps its length; the other adult keeps the age you set. So the optimizer never recommends a move for the other adult, and the “retire earlier” buttons on Household and the free Projection, Cash Needs and Tax Strategy sliders answer for that plan, not for both of you retiring earlier; each card says so. To move both ages, change them on Household, or use the full What-If Levers.

Re-baselined plans

• A re-baselined plan starts its tax history fresh. When you re-baseline on Plan vs. Actual, the new plan picks up from where your plan stood at the end of that year: your recorded balances, and what the plan held that you can't record, such as money from Roth conversions, cost basis, the five-year clock on each conversion, and any capital losses carried forward. It doesn't carry the history behind some year-to-year rules. Medicare's surcharges look at your income two years back and the ACA premium credit at last year's; the new plan's first years use their own income instead. Spending guardrails restart from the new plan's first year, last year's state income tax isn't deducted again, and a shortfall the old plan had already booked isn't carried. So the first year or two can differ a little from where the old plan was headed.
• A re-baselined plan carries a cost basis of up to 10 times an account's balance. The new plan records each account's cost basis as a share of its balance, and that share can be at most 10 times the balance (a 90% fall). If the old plan projected an account worth less than a tenth of what it cost by the year you re-baseline, the new plan starts it at 10 times its balance, so a later sale from that account counts a smaller capital loss than the old plan would have, and a little more tax. Nothing changes until that account is sold.

Suggested contributions

• A suggested contribution is checked against your whole plan first. Before the Actions and Budget pages suggest capturing an employer match, starting or raising a 401(k), or funding an HSA, ChartFI applies the change to your plan and runs its own checks again. If the change would add a new warning, or make one your plan already has worse by more than $1 (or 0.01% for a share, such as how much of a contribution your pay covers), ChartFI tries it once more as a smaller raise that stays the same every year. If that still trips a check, the suggestion isn't made, and you see one line instead that says what it would have done, such as pushing your plan's shortfall deeper. A catch-up the plan already counts as Roth (pay over the IRS wage threshold) doesn't stop one; the card says so. Nor does a Traditional IRA contribution losing its deduction stop an employer-match suggestion: as the plan counts no match you haven't recorded, that card is shown as information, saying the deduction is lost, with no tax figure. It doesn't stop a suggestion to start a 401(k) when you have recorded a match either, since an employer pays its match only on pay you defer: that card says how much match it earns and that the deduction is lost. A match paid in part where none was paid before counts as less unpaid match, not as a new warning. No other raise that would increase that year's tax is suggested, unless your Roth conversion takes its whole deduction: that one is shown with no tax figure too. So the pages can suggest a smaller raise than the IRS limits allow, or none at all.
• A suggested raise up to an IRS limit stays under it in every year. The IRS raises each limit in rounded steps while the plan grows your line with inflation, so in today's dollars a later year's limit can be lower. A suggestion to fill a 401(k) or HSA limit, and the setup sheet's 401(k) line, is held to the lowest it falls to before your next age step (64) or coverage step, and the card or note names it: in some years up to about $500 a year less than you could put in, more with a catch-up (about $1,200 at 60–63 at 3% inflation, up to about $1,800 at higher inflation rates).
• The check that your pay covers what comes out of it counts income tax in your first year only. ChartFI warns you when a working year's pay doesn't cover what comes out of it: what goes into a workplace plan such as a 401(k), and Social Security and Medicare tax. In the plan's first year it also counts the income tax on that pay. In later years it doesn't, so a year that would only come up short once income tax is taken out isn't flagged. Any year it does flag really is short. This matters most if you put most of your pay into a workplace plan, above all if your contribution grows faster than your pay.

• It isn't financial, tax, or legal advice. It's a planning tool. Big, irreversible moves — large Roth conversions, claiming decisions — are worth checking with a professional who knows your full situation.

An honest, updatable comparison. Every tool here is good at something; the right choice depends on what you value. Where a competitor is stronger, we say so.

The short version: ChartFI's edge is the guidance loop and tax-timing depth. If you want account aggregation or a long track record today, the premium DIY planners are strong, fair choices — and a spreadsheet still wins on raw flexibility.