🏦 401(k) Calculator
Watch your 401(k) grow with your contributions, the employer match and raises.
How it works
A 401(k) does not sit still while you feed it — your pay rises, so your contributions rise too. That is why this calculator runs year by year instead of using one formula. Each year it does four things: grows the existing balance by your expected return, works out your contribution as your percentage of that year's salary, adds your employer's match as their percentage of the same salary, and then gives you a raise before moving on.
Your own contribution has a legal ceiling. The IRS elective deferral limit for 2026 is $24,500 if you are under 50, and the calculator applies that cap every year. Money your employer puts in — the match — does not count toward your $24,500. The match matters more than it looks: contributing enough to collect the full match is an instant 100% return on that slice of your pay, before any market growth at all. Contributing less than the match percentage is, quite literally, handing back part of your salary.
One thing the balance does not show: tax. A traditional 401(k) is taxed when you withdraw in retirement; a Roth 401(k) was taxed on the way in. The pot grows the same way either way.
An example
Start with a $40,000 balance on an $85,000 salary. You contribute 8%, your employer matches 4%, pay rises 3% a year, investments return 7%, and this runs for 30 years. The balance at the end: $1,626,663.31.
The split is the interesting part. Your own contributions over the 30 years total $323,512.83. Your employer adds $161,756.41 — real money you did nothing extra to earn beyond contributing. And growth contributes $1,101,394.07, more than both sets of deposits combined. Note that the IRS cap never bites in this example — your largest yearly contribution, in the final year, is only about $16,025. On a much higher salary the $24,500 ceiling would start holding your percentage back.
Common questions
What is the 401(k) contribution limit for 2026?
For 2026 you can put in up to $24,500 of your own pay if you are under 50. From age 50 there is an $8,000 catch-up, taking it to $32,500, and under SECURE 2.0 workers aged 60 to 63 get a higher catch-up of $11,250 instead. Employer contributions sit outside this limit.
Should I contribute more than the employer match?
Get the full match first — nothing else in investing reliably doubles your money on day one. Beyond that it depends on your situation: expensive debt usually comes before extra investing, an emergency fund matters, and some plans have high fees worth avoiding once you have the match secured.
Is the employer match really free money?
Effectively yes, with one catch: vesting. The match is yours to keep, but many plans vest it over a few years, so leaving the job early can mean leaving some of it behind. Check your plan's vesting schedule before a job move — and remember your own contributions are always 100% yours.
Related calculators
This calculator gives estimates for learning. Rates, taxes and rules change, and your lender or the IRS has the final numbers — check big decisions against the real documents.