401(k) Calculator
Project your 401(k) balance at retirement — enter your current balance, salary, contribution percentage, employer match, years and expected return to see your future balance and the employer match you collect.
Estimate only, not financial advice. Projections assume a constant salary, contribution rate and annual return, which vary in reality; investment returns are not guaranteed and contribution limits apply. For planning only.
How a 401(k) grows: contributions, match, and compounding
A 401(k) is an employer-sponsored retirement account named after a subsection of the U.S. Internal Revenue Code. Each year three things flow into it: your own salary deferral, any employer match, and the investment return on the whole balance. Because the return compounds on top of every prior year's gains, the account grows slowly at first and then accelerates. The calculator above models this exactly: it takes your contribution percentage and the match as shares of salary, adds them every year, and grows the running balance at the annual return you choose until retirement. The single biggest levers are your contribution rate and the number of years invested — a one-percentage-point higher rate or three extra years can move the final figure by tens of thousands of dollars over a career.
Traditional 401(k) contributions are made with pre-tax dollars, so they lower your taxable income today and grow tax-deferred; you pay ordinary income tax when you withdraw in retirement. A Roth 401(k) flips this: you contribute after-tax dollars now and qualified withdrawals come out tax-free later. To see the pure compounding engine behind the projection, use the compound interest calculator; to check what a higher contribution does to your take-home pay, use the paycheck calculator.
2026 contribution limits (IRS)
The IRS sets how much you can defer from salary each year and adjusts it for inflation. For 2026 the elective-deferral limit rose to $24,500, with extra "catch-up" room once you reach certain ages. These are the figures the calculator's results should stay inside.
| 2026 limit (employee deferral) | Amount |
|---|---|
| Under age 50 | $24,500 |
| Age 50+ standard catch-up (+$8,000) | $32,500 |
| Age 60–63 "super" catch-up (+$11,250) | $35,750 |
| Combined cap incl. employer (415(c), under 50) | $72,000 |
The $72,000 figure is the total "annual additions" limit under IRC Section 415(c): your deferral plus the employer match plus any after-tax contributions, capped at the lesser of $72,000 or 100% of your pay. Counting catch-up room it can reach about $80,000 at 50+, or roughly $83,250 for ages 60–63. Note one 2026 change: if you are 50 or older and earned $150,000 or more in FICA wages the prior year, your catch-up must go into a Roth (after-tax) 401(k).
Employer match: free money, but only up to a cap
The match is the highest-return part of a 401(k) — it is an immediate, guaranteed gain on the money you put in. Employers usually express it as a formula. Two of the most common are shown below, on a $70,000 salary, alongside the contribution you must make to capture the full match.
| Match formula | You must contribute | Employer adds (on $70,000) |
|---|---|---|
| 50% of your contributions up to 6% of pay | 6% = $4,200 | $2,100 (3% of pay) |
| 100% on first 3% + 50% on next 2% | 5% = $3,500 | $2,800 (4% of pay) |
| Flat 3% of salary (non-elective) | any amount | $2,100 (3% of pay) |
Contributing less than the threshold leaves part of the match on the table. The rule of thumb: always defer at least enough to earn the full match before directing money elsewhere, then aim for a total of 10–15% of pay including the match.
Vesting: when the match is actually yours
Your own contributions are always 100% yours. The employer match, however, may be subject to a vesting schedule — you only keep it if you stay long enough. There are two common types.
| Vesting type | How it works | If you leave early |
|---|---|---|
| Immediate | Match is 100% yours right away | You keep all of it |
| Cliff (e.g. 3-year) | 0% until the cliff, then 100% | Leave before the cliff = keep nothing |
| Graded (e.g. 4-year) | 25% after year 1, 50%, 75%, 100% after year 4 | Keep the vested percentage only |
If you are weighing a job change, check your vesting schedule first — leaving a month before a cliff can forfeit thousands in matched dollars.
A fully worked example
Take the calculator's default scenario: a $25,000 starting balance, a $70,000 salary, a 6% personal contribution ($4,200/yr), a 3% employer match ($2,100/yr), a 7% annual return, and 25 years to retirement. Total added each year is $6,300. Running the year-by-year compounding ($balance × 1.07 + $6,300) for 25 years gives roughly $535,000 at retirement. Of that, about $105,000 is your own contributions, about $52,500 is the employer match, and the remaining ~$377,000 is investment growth — a clear picture of how compounding does most of the heavy lifting over a long horizon. Raise the contribution to 10% and the projection climbs past $660,000; the match and growth scale right along with it.
Taxes, withdrawals, and RMDs
A 401(k) is built for the long term, and the rules reward leaving it alone. Withdrawing before age 59½ generally triggers a 10% early-withdrawal penalty on top of ordinary income tax, with limited exceptions (certain hardships, disability, separation from service at 55+). Once you reach age 73 you must begin taking Required Minimum Distributions (RMDs) each year under the SECURE 2.0 Act; the start age rises to 75 in 2033. Missing an RMD can cost a 25% penalty on the shortfall (reduced to 10% if corrected promptly). Roth 401(k) money is no longer subject to RMDs during the owner's lifetime under current rules.
Don't ignore fees
Plan administration and fund expense ratios quietly reduce your return. A difference of just 1% in annual fees can shave a meaningful slice off a multi-decade balance — on the worked example above, dropping the net return from 7% to 6% lowers the projection by well over $80,000. Favor low-cost index or target-date funds where your plan offers them, and treat the "annual return" input as a return net of fees for a realistic result.
Benchmarks and a sensible return assumption
Long-term U.S. stock returns have historically averaged around 7% a year after inflation, but any single year swings widely and returns are never guaranteed. A conservative 6–7% keeps the projection grounded; model a lower figure too, so you see a realistic worst case. When you have a target balance in mind, use the IRA calculator to model a complementary tax-advantaged account alongside your 401(k).
For information only, not financial advice. Projections assume a constant salary, contribution rate and annual return, which vary in reality; investment returns are not guaranteed and IRS contribution limits apply. Verify current figures with the IRS and consult a qualified professional before acting.
Frequently asked questions
What is the 401(k) contribution limit for 2026?
For 2026 the employee salary-deferral limit is $24,500. If you are 50 or older you can add an $8,000 catch-up for $32,500 total, and a higher "super" catch-up applies at ages 60–63, raising it to $35,750. Including the employer match, the combined annual-additions cap is $72,000 (or 100% of pay, whichever is less). Note: high earners (FICA wages of $150,000+) must make catch-up contributions to a Roth 401(k).
What is the difference between a traditional and a Roth 401(k)?
A traditional 401(k) takes pre-tax contributions that lower your taxable income now and grow tax-deferred; you pay ordinary income tax on withdrawals in retirement. A Roth 401(k) uses after-tax contributions, so qualified withdrawals — including all the growth — come out tax-free. Traditional often wins if your tax rate will be lower in retirement; Roth often wins if it will be higher. Both share the same $24,500 deferral limit for 2026.
When can I withdraw from my 401(k) without penalty?
Generally at age 59½. Withdrawing earlier usually triggers a 10% early-withdrawal penalty plus ordinary income tax, with exceptions such as certain hardships, disability, or leaving your job in or after the year you turn 55. From age 73 you must take Required Minimum Distributions each year (the start age rises to 75 in 2033 under SECURE 2.0), or face a penalty on the amount you should have withdrawn.
What does vesting mean for my employer match?
Vesting is how long you must stay before the employer match is fully yours; your own contributions are always 100% yours. Plans use immediate vesting, cliff vesting (0% until a date such as 3 years, then 100%), or graded vesting (for example 25% per year over 4 years). If you leave before you are fully vested, you forfeit the unvested portion of the match — so check your schedule before changing jobs.
How much will my 401(k) be worth at retirement?
It depends on your balance, contributions, employer match, years invested and return. For example, $25,000 now plus 6% of a $70,000 salary with a 3% match, growing at 7% for 25 years, projects to roughly $535,000. Enter your own numbers above for an estimate.
How does employer matching work?
Many employers match part of your contribution — for instance 50% up to 6% of pay, or a flat 3% of salary. It is free money, so contributing at least enough to get the full match is usually worthwhile. Enter the match as a percentage of salary above to include it.
How much should I contribute to my 401(k)?
A common guideline is 10–15% of pay including the employer match, and at minimum enough to capture the full match. Increasing your percentage even a little has a large effect over decades thanks to compounding — try different rates above to see it.
What return should I assume?
Long-term stock-market returns have historically averaged about 7% a year after inflation, though any given year varies widely and returns are not guaranteed. Using a conservative figure like 6–7% gives a realistic projection; adjust it above to see best and worst cases.