How to use this calculator
- Find your plan's matching formula in its summary plan description or your benefits portal. It reads like "100% of the first 3% of pay and 50% of the next 2%". Enter each tier; a plan with one tier has no second.
- Enter your yearly pay, how often you are paid, your age at the end of the year and the percent of each paycheck you contribute, pre-tax and Roth together.
- Say when your plan matches. If it matches each paycheck, check whether it has a year-end true-up: that decides whether reaching the limit early costs you anything.
- Enter your balance from your latest statement, the age you plan to retire, and how much of what you put in goes to Roth (0% if it is all pretax). The tax rate in retirement is the share of each pretax dollar you withdraw that goes to federal and state tax; try a few to see where Roth and pretax trade places.
- Partway through the year, open More options: enter the paychecks already paid and what you have put in so far, and the answer becomes the rate for the rest of the year. The same section takes a job started during the year, contributions at another job, a yearly cap on the match, and student loan payments your plan matches. It also holds your raises, inflation, other employer contributions such as profit sharing, your filing status and state tax rate for the tax pretax saves you, and after-tax contributions if your plan takes them.
How it's calculated
Your employer match is figured from what you actually put in. Each paycheck, your contribution is your rate times that paycheck's pay, rounded to the cent, until your contributions for the year reach the limit on elective deferrals: $24,500 for 2026, more from age 50 with a catch-up contribution, less whatever you put in at another job. The formula then applies to that contribution and that paycheck's pay. A plan may count pay only up to $360,000 a year for the match, so once your pay for the year passes it, later paychecks get no match. Your contributions continue on those paychecks until you reach the limit, unless your plan stops them there, which the IRS describes as not common.
An example
Take $65,000 a year, paid every two weeks, and the formula a safe harbor 401(k) uses at its simplest: 100% of what you put in up to 3% of pay, then 50% of the next 2%. Each paycheck is $2,500.00. At 6% you put in $150.00; the plan matches all of the first 3% of pay and half of the next 2%, $100.00. Over the year that is $3,900 from you and $2,600 from your employer, the whole match. Any rate from 5% to 39% gets it: below 5% the match falls, and above 39% you would reach the limit before your last paycheck.
When a high rate loses match
Now take $150,000 a year, every two weeks, a match of 50% up to 6% of pay, and a 20% rate. You reach the $24,500 limit with paycheck 22 (about November). If the plan matches each paycheck with no true-up, the 4 paychecks after that have no contribution and no match: you get $3,769 of $4,500. With a year-end true-up the plan pays the difference after the year ends, and you get $4,500. Any rate from 6% to 16% gets the whole match without one.
Payroll rounds each paycheck to the cent, so the year's figures can differ by a few cents from a percent of yearly pay. The calculator does the same, and treats a difference of a cent a paycheck or less as rounding rather than lost match.
Student loan payments
If your plan offers a student loan match, your payments on qualified student loans count as if they were contributions when the plan figures the match, up to the $24,500 limit (or your pay, if less) minus what you contributed. The calculator adds what the formula pays on those payments to the year's match, as one payment after the year ends.
Growing to retirement
Each later year is figured the way this year is, paycheck by paycheck, at the same rate: your pay rises by the raise you enter each January, the limits rise, and your age sets the catch-ups. The account grows at the return you enter. Contributions arrive with each paycheck, so in the year they go in they earn about half a year's return; a true-up or once-a-year match goes in early the next year. In the example above, with $40,000 in the account, a 2.5% raise each year and a 7% return, the account would hold $49,528 at the end of 2026, $59,890 at the end of 2027 and $71,150 at the end of 2028, and about $1,128,935 by 65: $171,220 more from you, $114,147 from your employer and $803,567 of growth. That is about $538,211 in today's dollars at 2.5% inflation.
How the limits rise
The law sets each limit from a base amount raised by inflation: the consumer price index for July to September of the year before, over the same months of a base year, with any increase rounded down to a whole step ($500 for the limit on what you put in and the catch-ups, $1,000 for the yearly limit on everything paid in, $5,000 for the pay a plan can count). The IRS's published figures follow that method every year, and the calculator uses it for the years the IRS has not published yet. For 2027, from inflation already published, the limit on what you put in comes to $25,500; by 2036, at the inflation you enter, about $31,500.
Roth or pretax
A pretax contribution lowers your taxable income now and is taxed when you take it out; a Roth contribution is taxed now and comes out tax-free. To compare them at the same cost to you, the calculator figures the tax a pretax contribution saves you this year from two federal returns, with and without it, and invests that saving in a taxable account whose gains are taxed when you retire. In the example, the tax a pretax contribution saves you this year is $468, 12.0% of what you put in. At a 12.0% tax rate on withdrawals, Roth leaves about $5,822 more after tax , and the two come out even at a 10.8% rate in retirement. The taxable account's gains are taxed, which is why that rate sits a little below the tax saved today. From 2026, someone whose Social Security wages from the employer were over the Roth catch-up wage threshold the year before must make catch-up contributions as Roth; the calculator applies that rule in every year it reaches.
After-tax contributions
Some plans take after-tax contributions, which you may be able to convert to Roth. They fit under the yearly limit on everything paid into your account, $72,000 for 2026, together with your own contributions and your employer's, but not your catch-ups. On $200,000 of pay with a match of 50% up to 6%, putting in $24,500 leaves $42,500 of room. From 50, a plan can count up to the catch-up amount of what you put in as catch-ups when after-tax money fills the limit, so at 55, putting in $24,000 on $240,000 of pay, the room is $48,800.
Assumptions and limits
- Your pay is the same every paycheck: no raise, bonus or overtime during the year. A plan that leaves bonuses or overtime out of the pay it matches on would match less than shown.
- The plan counts all your pay for the match, up to $360,000 for 2026, and stops counting pay once the year's pay passes that limit. Your contributions continue after that unless you mark that your plan stops them. A plan may instead spread the limit evenly over the year's paychecks, which the rules also allow; for high earners that can change the match by a few hundred dollars.
- What you put in earlier this year is spread evenly across the paychecks already paid, and was matched by the same formula.
- Contributions are a percent of each paycheck, rounded to the cent.
- A true-up or a once-a-year match is paid after the year ends, and some plans pay it only to people still employed then.
- The plan year is the calendar year.
- The match follows the formula you enter. The calculator does not run the tests that can reduce matches for highly compensated employees.
- Vesting is not modeled: if you leave before the match vests, you may keep less of it than shown.
- The $72,000 yearly limit on everything paid into your account, from you and your employer, counts only this employer's plan. The calculator flags it if you are over it rather than reducing the figures, because your plan decides which amount it cuts.
- Your contribution rate stays the same every year, your pay rises by the raise you enter each January, and you stay at this employer with the same match until you retire. Contributions stop at the end of the year before you turn the retirement age.
- After 2026, the IRS limits rise the way the law indexes them. The IRS had not published the 2027 limits when this page was built. A year whose inflation is already published uses that inflation, and later years use the inflation you enter.
- Contributions go in through the year, so they earn about half a year's return in the year they are made. A true-up or once-a-year match goes in early the next year.
- The match and other employer contributions count as pretax (a plan may offer Roth matching).
- One tax rate stands for all your withdrawals in retirement. In practice the rate depends on your other income, Social Security, required minimum distributions and where you live then. The 10% additional tax on pretax money taken before 59½ is not counted.
- The tax a pretax contribution saves you is figured for 2026 on the standard deduction, before credits (and, filing jointly, with a spouse your age), and held for later years with your filing status.
- Comparing Roth and pretax, the tax pretax saves you is invested unless you choose otherwise, and its gains are taxed once, at retirement; yearly tax on that account's dividends is not charged, which favors pretax slightly.
- For the rule that sends some catch-ups to Roth, last year's pay from this employer stands for last year's Social Security wages.
- Roth money counts as tax-free in retirement: earnings come out tax-free once you are 59½ and five tax years have passed since your first Roth contribution (or on death or disability).
- Fees are taken out of the return you enter.
- After-tax room uses this employer's plan only. Your plan may cap after-tax contributions lower, and the test that can refund contributions to highly paid employees is not run.
- It does not model a formula with three or more tiers, an increase in your rate during the year or over the years, a plan's own cap on the rate you can choose, Roth matching, vesting, loans or job changes in later years, the 403(b) 15-year catch-up, SIMPLE IRAs, SEP IRAs, solo 401(k)s or governmental 457(b) plans.
Input field details
What to enter in each box, where to find the number, and how this calculator treats it. When two calculators give different answers from the same numbers, it's usually because they handle one of these differently.
Your yearly pay
Your yearly pay at this job, before taxes and deductions, including what you put in your 401(k). For a job started this year, enter the full-year amount.
Where to find itYour offer letter or a pay stub: gross pay per paycheck times the paychecks in the year.
How this tool treats itThe pay is split evenly across your paychecks, with any leftover cents on the last one. A plan can count only so much pay a year for contributions and the match: $350,000 for 2025 and $360,000 for 2026. Once your pay passes that, later paychecks count no pay, so nothing goes in from them and they get no match.
Allowed range$1,000 to $2,000,000
Not includedRaises, bonuses and overtime during the year. A plan that leaves bonuses or overtime out of the pay it matches on would match less than shown.
Your plan stops contributions once your pay passes the pay limit
Leave off unless your plan says contributions stop when your pay for the year reaches the limit on pay a plan can count ($360,000 for 2026). Shown only when your pay is above it.
Where to find itYour plan’s summary plan description, or your plan administrator.
How this tool treats itOff, your rate applies to every paycheck until you reach the yearly limit, which is how the IRS says plans work unless their terms say otherwise. Either way, the match counts only pay up to the limit.
How often you’re paid
Your pay schedule. Pick 27 or 53 paychecks if your employer pays that many this year.
Where to find itYour pay stubs, or your employer’s payroll calendar.
How this tool treats itA plan that matches each paycheck figures the match on that paycheck’s pay and contribution. A 27th or 53rd paycheck spreads the same yearly pay over one more paycheck. The month shown for weekly and biweekly paychecks is approximate, since the calculator does not know your paydays.
Your age at the end of the year
The age you will be on December 31 of the tax year.
How this tool treats itA catch-up contribution is an extra amount you can put in above the yearly limit if you are 50 or older by the end of the year: $7,500 for 2025 and $8,000 for 2026. At ages 60 to 63 a larger amount replaces it: $11,250 for 2025 and $11,250 for 2026. At 64 it returns to the age-50 amount.
Allowed range18 to 100
You contribute
The percent of each paycheck you put in your 401(k), pre-tax and Roth together.
Where to find itYour plan’s enrollment site, or the deferral line on a pay stub.
How this tool treats itWhat you put in from your pay is an elective deferral. The yearly limit on elective deferrals is $23,500 for 2025 and $24,500 for 2026, plus any catch-up, and it counts what you put in at every employer that year. Your contributions stop when you reach it, and a plan that matches each paycheck stops matching with them. Each paycheck’s contribution is rounded to the cent.
Allowed range0% to 75%
Not includedAfter-tax contributions above the limit, and a plan’s own cap on the rate.
Employer matches, up to a percent of pay
The first tier of your plan’s formula: how much your employer adds for each dollar you put in, and the percent of pay it applies to. For “100% of the first 3% of pay”, enter 100% and 3%.
Where to find itYour plan’s summary plan description, under “matching contributions”.
How this tool treats itAn employer match is money your employer puts in your account because you contribute. The matching formula applies to the dollars you actually put in, never to more than the tier’s percent of your pay.
Allowed range0% to 200%, up to 0% to 20% of pay
Then matches, of the next percent of pay
The second tier, if your plan has one. For “then 50% of the next 2% of pay”, enter 50% and 2%. Enter 0 if there is no second tier.
Where to find itYour plan’s summary plan description.
How this tool treats itThe default formula, 100% of the first 3% of pay and 50% of the next 2%, is the safe harbor basic match: a formula set in the regulations that lets a plan skip the yearly tests comparing what higher- and lower-paid employees put in and receive. A second tier that matches more than the first is allowed.
Allowed range0% to 200%, of the next 0% to 20% of pay
When your plan matches
Whether your plan figures the match each paycheck or once on the year’s totals, and whether it makes up a shortfall after the year ends.
Where to find itYour plan’s summary plan description. Look for “true-up” or for the period the match is figured over.
How this tool treats itA true-up is a payment after the year ends that brings your match up to what the formula gives on the year’s totals. Without one, a plan that matches each paycheck pays nothing for a paycheck with no contribution, so reaching the limit early ends the match early. A true-up never takes money back. Some plans pay a true-up or a yearly match only to people still employed then.
Yearly cap on the match
The most your employer will match in a year, if your plan sets a dollar cap. Enter 0 if it does not.
Where to find itYour plan’s summary plan description.
How this tool treats itThe cap includes any student loan match and true-up, and takes from the last payment first. It is separate from the IRS’s yearly limit on everything paid in to your account (your contributions other than catch-ups plus the match): $70,000 for 2025 and $72,000 for 2026, or your pay if less. The calculator flags that limit but does not reduce the figures, because your plan decides what it cuts.
Allowed range$0 to $100,000
Plan matches catch-up contributions
Leave on if your plan’s formula applies to everything you put in. Turn off if it matches only up to the base yearly limit.
Where to find itYour plan’s summary plan description.
How this tool treats itWhen off, what you put in above the base limit gets no match, even if the formula’s percent of pay has room for it.
You can make catch-up contributions
Turn off if your plan has no catch-ups, or if your Social Security wages from this employer last year were over the Roth catch-up threshold and your plan has no Roth option.
Where to find itBox 3 of last year’s W-2 from this employer, and your plan’s summary plan description.
How this tool treats itSomeone whose Social Security wages from the employer the year before were over a threshold (2025 wages over $150,000, for 2026) can make catch-ups only as Roth. In a plan with no Roth option, that person can make none.
Your plan lets you choose rates in
The smallest step your plan allows for your contribution rate.
Where to find itYour plan’s enrollment site.
How this tool treats itThe rates that get the whole match, and the rate that reaches the limit, are found on these steps.
Paychecks from this job this year
If you started this job during the year, the number of paychecks it will pay you this year. Leave at 0 for a full year.
Where to find itYour start date and your employer’s payroll calendar.
How this tool treats itYour yearly pay is still entered as a full year’s pay; the calculator counts only these paychecks, and the plan’s formula and limits apply to the pay from them.
Allowed range0 to 53
Paychecks already paid this year
The paychecks from this job you have already been paid this year, if you are changing your rate partway through.
Where to find itYour latest pay stub.
How this tool treats itYour rate applies to the paychecks after these.
Allowed range0 to 53
You’ve put in so far this year
What you have put in this plan this year, across the paychecks already paid.
Where to find itThe year-to-date 401(k) line on your latest pay stub.
How this tool treats itIt is spread evenly across the paychecks already paid, and those paychecks are matched by the same formula. It is read only when paychecks already paid is above 0.
Allowed range$0 to $100,000
Put in at another job this year
What you put in a 401(k), 403(b), SIMPLE IRA or SARSEP at another employer this year. Not a 457(b), which has its own limit.
Where to find itBox 12 of the W-2 from that job, or its final pay stub.
How this tool treats itIt shares your yearly limit, so it leaves this plan less room. It does not change which of this plan’s contributions count as catch-ups, since each plan decides that against its own limit.
Allowed range$0 to $100,000
Student loan payments this year, and whether your plan matches them
Payments you made this year on student loans you owe, for your own, your spouse’s or a dependent’s education, and whether your plan matches them.
Where to find itYour loan servicer’s statements. Your plan’s summary plan description says whether it offers a student loan match.
How this tool treats itA student loan match counts these payments as if they were contributions, at the same rate. Only payments up to the base yearly limit (or your pay, if less), minus what you put in this year here and at any other job, count. The calculator counts it as one payment after the year ends; your plan sets the deadline to claim it.
Allowed range$0 to $100,000
Your 401(k) balance now
What is in this plan now, pretax and Roth together. Leave out other employers’ plans and IRAs.
Where to find itYour latest statement from this plan, or the plan’s website: the total account balance.
How this tool treats itIt grows at the yearly return you enter from today. The part you enter as Roth is counted as tax-free when you take it out in retirement; the rest is taxed at the rate you enter for withdrawals.
Allowed range$0 to $10,000,000
Of that, Roth
The part of your balance that is Roth money.
Where to find itYour statement, which lists Roth and pretax money as separate sources.
How this tool treats itThe rest of the balance is counted as pretax. An amount above the balance is counted as the whole balance.
Allowed range$0 to $10,000,000
Retire at
The age at which you expect to stop contributing to this plan.
How this tool treats itContributions stop at the end of the year before you turn this age, and the balance is shown as of January 1 of the year you turn it. Catch-up contributions follow the age you reach each year: the larger amount from 60 to 63, then the age-50 amount again from 64.
Allowed range19 to 75
Yearly return
The yearly return you expect on this plan’s investments, after fund fees.
How this tool treats itYour contributions and a match paid each paycheck go in through the year, so they earn about half a year’s return in the year they are made, and a full year’s after that. A true-up or a once-a-year match goes in at the start of the next year. Returns are an assumption, not a forecast.
Allowed range0% to 20%
Yearly raises
The raise you expect each year, as a percent of your pay.
How this tool treats itYour pay rises by this much each January after this year. Your contributions and the match follow your pay, up to the yearly limits.
Allowed range0% to 10%
Tax rate on your 401(k) withdrawals in retirement
The share of each pretax dollar you take out in retirement that you expect to go to federal and state income tax.
How this tool treats itOne rate stands for all your withdrawals: the pretax balance times one minus this rate, plus the Roth balance, is the value after tax. In practice the rate depends on your other income, Social Security, required minimum distributions and where you live then.
Allowed range0% to 50%
Not includedThe 10% additional tax on pretax money taken out before 59½.
Filing status
Your filing status this year.
Where to find itThe top of last year’s Form 1040, if nothing has changed.
How this tool treats itIt sets the federal tax a pretax contribution saves you this year, figured on the standard deduction and before credits. Filing jointly, your spouse is taken as your age. The same saving, as a share of what you put in, is used for later years.
Other taxable income
Income on your return besides this pay: a spouse’s pay after their own 401(k), interest, the taxable part of Social Security.
Where to find itLast year’s Form 1040: total income, less your wages from this job.
How this tool treats itUsed only for the tax a pretax contribution saves you this year.
Allowed range$0 to $2,000,000
State income tax rate
Your state’s income tax rate on your top dollars of income, which is the rate this extra income would be taxed at. Leave it at 0 to leave state tax out.
Where to find itYour state’s rate table for your filing status, at your income. It is usually higher than your average rate, which is last year’s state tax divided by your income.
How this tool treats itApplied to the contributions that could go in as pretax or Roth this year, and added to the federal tax a pretax contribution saves. Enter 0 if your state taxes 401(k) contributions when you make them, as Pennsylvania does.
Allowed range0% to 15%
Tax rate on investment gains
The tax rate on the gain in a taxable investment account when you sell, federal and state together.
How this tool treats itComparing Roth and pretax, the tax pretax saves you is invested in a taxable account, and its gain is taxed once at this rate when you retire. Long-term gains are taxed at 0% on taxable income up to $49,450 and 15% up to $545,500 (2026, single), plus your state’s rate.
Allowed range0% to 40%
Not includedYearly tax on the account’s dividends and interest, which favors pretax slightly.
The tax pretax saves you now
Whether you would invest the tax a pretax contribution saves you, or spend it.
How this tool treats itInvested, Roth and pretax cost you the same each year: Roth’s tax comes out of your pay, and pretax’s saving goes into a taxable account at your yearly return. Spent, Roth costs you more each year, so the comparison shows what that extra buys.
Inflation
The yearly rise in prices you expect.
How this tool treats itThe IRS limits for years it has not published follow the law’s formula: the base amount times the rise in the CPI-U since the base period, with the increase rounded down to a multiple of $500 (what you put in and the catch-ups), $1,000 (everything paid in) or $5,000 (the pay a plan can count and the Roth catch-up threshold), and never below the year before. The first such year rests on inflation already published, later years on the rate you enter. It also sets today’s dollars.
Allowed range0% to 10%
Show in today’s dollars
Turn on to show future figures in today’s dollars.
How this tool treats itA future figure is divided by the rise in prices from now to then at the inflation rate you enter, rounded to the cent and then to the dollar.
Other employer contributions
What your employer puts in apart from the match, as a percent of pay: profit sharing, or a fixed contribution such as the Thrift Savings Plan’s automatic 1%.
Where to find itYour plan’s summary plan description, or the employer contribution lines on your statement.
How this tool treats itApplied to the pay the plan counts each year, up to the yearly limit on pay a plan can count, and counted as pretax. This year it counts only on the paychecks still ahead.
Allowed range0% to 25%
After-tax contributions
Turn on if your plan takes after-tax contributions (money that is neither pretax nor Roth and does not count toward the yearly limit on what you put in), and enter what you have put in that way this year.
Where to find itYour plan’s summary plan description, and the after-tax line on your latest statement.
How this tool treats itThe room is the yearly limit on everything paid in ($70,000 for 2025 and $72,000 for 2026), or your pay at this job if less, minus what you put in other than catch-up contributions, the match, other employer contributions and after-tax money already in. If you are 50 or older, up to the catch-up amount of what you put in can count as catch-ups when after-tax money fills the limit. It is shown for this year only and is not added to the projection.
Allowed range$0 to $100,000 put in so far
Not includedYour plan’s own cap on after-tax contributions, and the yearly test that can refund them to highly paid employees.
Questions
How much will my 401(k) be worth when I retire?
Is Roth or pretax better for my 401(k)?
How does the 401(k) limit change each year?
Do catch-up contributions have to be Roth?
What are after-tax 401(k) contributions?
What is a 401(k) true-up?
Can contributing too much lose me part of my match?
Do catch-up contributions get matched?
What is the age 60 to 63 catch-up?
Does the match count toward the $24,500 limit?
Can my student loan payments get a 401(k) match?
What if I change jobs during the year?
Do my contributions stop when my pay passes $360,000?
What happens if I spread contributions evenly?
Version history
- October 30, 2026 (version 2.0.0): Now a 401(k) calculator: the balance your rate reaches by retirement and its after-tax value, with raises and the IRS limits indexed, Roth or pretax compared, and after-tax room. This year's match is unchanged.
- October 17, 2026 (version 1.0.0): First version. Your 401(k) match paycheck by paycheck, the rates that get all of it, the rate that reaches the limit without losing any, catch-ups, the pay limit, a job started this year and student loan matching, 2025 and 2026.