Simple 401k Calculator
Updated August 2026 — reflects the 2026 IRS contribution limits.
Five inputs, one instant answer. No “Calculate” button, no sign-up — your projection updates live as you move each slider, with employer match and 2026 IRS limits built in.
More assumptions
Your 401(k) balance by age
Milestones on the way to retirement, using the assumptions above. A common benchmark: 1× salary saved by 30, 3× by 40, 6× by 50, and 8–10× by retirement.
| Age | Balance | You’ve put in | Employer match | Growth |
|---|
401k calculator with employer match
The match is the highest-return money you will ever earn — an instant 25–100% gain before any market growth. Two numbers to know:
Minimum contribution to capture the full match
Contribute at least this much of your salary. Below it, you’re declining free money.
Lifetime employer match at your current rate
Total your employer adds between now and retirement — plus everything it compounds into.
Roth 401k vs Traditional 401k
Same investment, same match, different tax timing. The projection above works for both — what changes is when you pay tax.
| Traditional 401(k) | Roth 401(k) | |
|---|---|---|
| Contributions | Pre-tax | After-tax |
| Tax break today | Yes — lowers taxable income | No |
| Withdrawals in retirement | Taxed as income | Tax-free (qualified) |
| Employer match goes to | Pre-tax account | Pre-tax account |
| Best if you expect | Lower tax rate in retirement | Higher tax rate in retirement |
What it costs per paycheck
A Traditional 401(k) contribution is pre-tax, so your take-home pay drops by less than the amount you save.
Goes into your 401(k) each paycheck
Your take-home pay actually drops by
Traditional (pre-tax). With a Roth 401(k), take-home drops by the full contribution.
How this 401(k) calculator works
This calculator projects your 401(k) balance by compounding three things every month until you retire: your own contributions, your employer’s match, and investment growth on the running balance. Your salary grows each year, your deferrals are capped at the IRS limit for your age, and the result updates instantly whenever you change an input.
The engine is a month-by-month simulation, not a single interest formula. Each month it takes your current balance, adds one month of your contribution and one month of employer match, then applies one month of growth. In plain terms:
New balance = old balance × (1 + annual return ÷ 12) + your monthly contribution + monthly employer match.
It repeats that from your current age to your retirement age. Once a year your salary grows by your expected raise, which nudges up both your contribution and the match. Your deferral is capped at the 2026 IRS limit for your age, and the combined employee-plus-employer total is capped at $72,000. Estimated monthly income in retirement uses the 4% rule — a common guideline that draws 4% of your final balance per year.
A worked example
Take the default scenario: you’re 30, earn $70,000, already have $25,000 saved, and defer 8% of pay. Your employer matches 100% of your first 4%. You assume 7% annual returns, 3% raises, and retirement at 65.
- In year one you defer 8% of $70,000, or $5,600 — about $467 a month.
- Your employer adds 100% of the first 4% of salary, or $2,800 — about $233 a month.
- That’s roughly $700 a month flowing in, on top of 7%-a-year growth on everything already invested.
- Compound that for 35 years, with raises lifting the dollar amounts each year, and the projection lands near $2.07 million — around $6,900 a month under the 4% rule.
Every number on the page is nominal (future dollars) unless you switch on “Show result in today’s dollars” under More assumptions, which discounts the projection for inflation so you can see what the balance would actually buy now.
2026 401(k) contribution limits
For 2026 you can contribute up to $24,500 to a 401(k) from your own paycheck. If you’re 50 or older, a catch-up raises your limit to $32,500. If you’re 60 to 63, a higher “super catch-up” lets you reach $35,750. Employer contributions bring the combined annual cap to $72,000.
| Year | Under 50 | Age 50+ | Ages 60–63 | Combined cap |
|---|---|---|---|---|
| 2026 | $24,500 | $32,500 | $35,750 | $72,000 |
The base limit is the most you can defer from your salary. Once you turn 50, a catch-up contribution of $8,000 lifts your ceiling to $32,500. A newer “super catch-up” under SECURE 2.0 gives savers aged 60 to 63 an even larger allowance — $35,750 in total — before it drops back to the standard 50-plus catch-up at 64.
The combined cap of $72,000 counts everything that lands in the account in a year: your deferrals plus your employer’s match and any profit sharing. This calculator applies the right ceiling for your age automatically, and flags a note if your contribution rate would push past it. The IRS usually adjusts these figures for inflation each autumn, so they tend to rise a little year to year.
Source: 2026 figures reflect the IRS contribution limits announced in November 2025.
How employer 401(k) matching works
An employer match is money your company adds to your 401(k) based on what you contribute. A common formula is “100% up to 4%” — your employer puts in a dollar for every dollar you defer, on the first 4% of your salary. It is an immediate return you cannot get anywhere else in investing.
Match formulas vary. “100% up to 4%” doubles your first 4% of pay. “50% up to 6%” adds fifty cents per dollar on your first 6% — the same 3% of salary, but you have to contribute more to capture it. Whatever the shape, the rate that captures the full match is the number to know, and the calculator shows it for your plan.
Vesting: when the match is truly yours
Money you contribute is always 100% yours. The employer’s match may come with a vesting schedule that decides how much you keep if you leave:
- Cliff vesting — you own 0% of the match until a set date (say, three years of service), then 100% all at once.
- Graded vesting — you own a rising share each year, for example 20% per year until you’re fully vested after five.
Leave before you’re vested and you forfeit the unvested portion of the match, though never your own contributions or their growth.
The “true-up”
Some plans add a year-end true-up. In plans that match each paycheck, maxing out early and stopping can cost you match on later paychecks — a true-up fixes that by recalculating the match on your full-year contribution and paying any shortfall. Without one, spreading contributions across the whole year captures every matching dollar.
How much should you have in your 401(k) by age?
A widely cited benchmark suggests having about 1× your salary saved by 30, 3× by 40, 6× by 50, 8× by 60, and 10× by 67. These are rough guideposts, not rules. Your real target depends on when you plan to retire, your other savings, and the income you want to replace.
| Age | Target (× salary) | At a $70,000 salary |
|---|---|---|
| 30 | 1× | $70,000 |
| 40 | 3× | $210,000 |
| 50 | 6× | $420,000 |
| 60 | 8× | $560,000 |
| 67 | 10× | $700,000 |
Treat these multiples as a sanity check, not a scoreboard. Someone who started late, carries a pension, or plans to work past 67 has a different picture. What matters more than hitting a birthday number is your savings rate and capturing your full match — the projection above shows how quickly a higher rate closes the gap.
Want to compare your balance against typical savers your age? See our 401(k) balance by age guide for average and median balances at each decade.
What return should you assume?
There is no guaranteed number, but many long-term projections use about 7%. The S&P 500 has returned roughly 10% a year on average over the long run, and around 7% once you subtract inflation. Choosing a lower, more conservative rate builds in a margin of safety if future returns disappoint.
The calculator defaults to 7% because it’s a reasonable stand-in for long-run stock returns after inflation. If you leave the projection in nominal dollars, you might use a higher figure closer to 10%; if you switch on “today’s dollars,” 7% already reflects roughly a 3% inflation drag. The honest answer is that nobody knows the next 35 years, so the smart move is to try a range — say 5% to 8% — and see how sensitive your result is.
One caveat worth remembering is sequence-of-returns risk: near retirement, the order of returns matters as much as the average, because a steep drop right after you stop working is harder to recover from than the same drop at 30. A projection assumes a smooth average; real markets don’t cooperate. Building in a conservative return and a cushion beyond the 4% rule is how many savers hedge that uncertainty.
Traditional vs Roth: which should you choose?
It comes down to when you pay tax. Traditional contributions are pre-tax and lower your taxable income now, but withdrawals are taxed later. Roth contributions are after-tax with no break today, yet qualified withdrawals are tax-free. Roth tends to favor savers who expect a higher tax rate in retirement than they pay today.
The comparison table earlier on this page covers the essentials, and note that your employer’s match always lands in a pre-tax (Traditional) bucket even if your own contributions are Roth. Many savers split the difference and contribute to both. For a side-by-side projection of after-tax retirement income under each choice, use our dedicated Roth 401(k) calculator.
What this calculator doesn’t cover
This tool is built to do one thing well: project your balance growth to retirement. It deliberately leaves out investment fees, withdrawal taxes, early-withdrawal penalties, 401(k) loans, and required minimum distributions. Each of those deserves its own math, so we build a dedicated calculator for each and keep this one simple and fast.
- Investment fees. Fund and plan fees quietly compound against you — even 1% a year can cost six figures over a career. This projection assumes your return is net of fees, so subtract your fees from the return you enter.
- Early withdrawals. Taking money out before age 59½ usually means income tax plus a 10% penalty. See the 401(k) early withdrawal calculator to estimate the hit.
- Withdrawal taxes in retirement. Traditional withdrawals are taxed as ordinary income. Our 401(k) withdrawal tax calculator models the federal and state bite.
- 401(k) loans. Borrowing from your plan has its own trade-offs and repayment math — see the 401(k) loan calculator.
- Required minimum distributions. Starting at age 73 you must withdraw a minimum each year. Estimate yours with the 401(k) RMD calculator.
Everything here is for education only and isn’t investment, tax, or legal advice. Projections use assumptions you control; real returns, taxes, and rules will differ. For decisions about your own money, talk to a qualified professional.