401(k) Calculator
Project your 401(k) balance year by year: your contributions, your employer's match, and compound growth, with the 2026 contribution limits built in.
Last updated: October 2026
Your 401(k) inputs
How a 401(k) grows
A 401(k) grows from three streams at once: your contributions, your employer's match, and compound returns on everything already in the account. Each year, new money goes in and the whole balance compounds. Over decades the compounding stream usually becomes the largest of the three, which is why starting early beats contributing more later: money invested at 25 has twice as long to compound as money invested at 35.
The 2026 contribution limits
For 2026 you may contribute up to $24,500 of your own salary (the elective deferral limit). Workers 50 and older can add an $8,000 catch-up contribution for a $32,500 total, and workers ages 60 to 63 get a super catch-up of $11,250 ($35,750 total) under the SECURE 2.0 rules. Employer matches sit outside your personal limit: they count toward a separate $70,000 combined cap. This calculator caps your entered contribution at $24,500 and tells you when it does.
The match is free money: do the math
A typical match formula reads "50% up to 6%": the employer adds fifty cents for every dollar you contribute, on contributions up to 6% of your salary. On an $80,000 salary, contributing 6% ($4,800) earns a $2,400 match: an instant 50% return before any market growth. Contributing only 3% would earn just $1,200 and leave $1,200 of free money unclaimed every year. The iron rule of 401(k)s: contribute at least enough to capture the full match before doing anything else with retirement money.
| 2026 limit | Under 50 | 50+ | Ages 60-63 |
|---|---|---|---|
| Your elective deferral | $24,500 | $32,500 | $35,750 |
| Catch-up amount | $0 | $8,000 | $11,250 |
Worked example
Start with $10,000, earn $80,000, contribute 10% ($8,000, under the $24,500 cap), get a 50% match up to 6% (0.50 x $4,800 = $2,400), and earn 7% for 10 years. Annual additions total $10,400. Compounding year by year, the balance reaches roughly $157,000: about $10,000 starting money plus $104,000 of contributions plus roughly $43,000 of growth. Stretch the same inputs to 30 years and compounding dominates: the balance passes $1,000,000 with growth contributing more than all contributions combined.
What this projection leaves out
Real life adds wrinkles. Salary raises would lift contributions over time, so a flat salary understates the total. Investment fees drag returns: every 1% in fees costs roughly a quarter of the ending balance over 30 years. Market returns are lumpy, not the smooth 7% shown here, and the sequence of returns matters near retirement. Taxes are ignored entirely: traditional 401(k) money is taxed on withdrawal. Treat the projection as a planning compass, not a promise, and rerun it with conservative returns to see your margin of safety.
Vesting, loans, and other fine print
Your own contributions are always 100% yours, but employer matches often vest over a schedule: leave after one year with a three-year cliff and the match money stays behind. Check your plan's vesting schedule before changing jobs, since a few months of timing can be worth thousands. Most plans also allow loans against your balance, which sounds tempting and is usually a mistake: you repay with after-tax dollars, the borrowed money misses market growth, and leaving your job can force immediate repayment. Finally, name a beneficiary and keep it current: 401(k) money passes outside your will, so an ex-spouse listed a decade ago legally inherits over your current wishes.
401(k) FAQs
What is the 401(k) contribution limit for 2026?
The 2026 elective deferral limit is $24,500. If you are 50 or older you can add an $8,000 catch-up contribution ($32,500 total), and ages 60 to 63 get a super catch-up of $11,250 ($35,750 total). This calculator caps your contribution at $24,500 and flags it.
How does an employer match work?
A common formula is 50% of your contributions up to 6% of your salary: if you contribute 6% of an $80,000 salary ($4,800), the employer adds $2,400. Contributing less than the match cap leaves free money on the table, so always contribute at least enough to capture the full match.
What return should I assume?
A diversified stock-heavy portfolio has returned roughly 7% per year after inflation over long periods, and about 10% before inflation. This calculator uses a nominal return you enter, so for a conservative planning number use 6 to 7%.
Should I choose Roth or traditional 401(k)?
Traditional contributions cut your taxable income now and are taxed in retirement; Roth contributions are taxed now and grow tax-free. Rough rule: if your tax rate will be lower in retirement, traditional usually wins; if you are early in your career or expect higher future income, Roth often wins.
What happens to my 401(k) if I change jobs?
You can leave it, roll it into your new employer's plan, or roll it into an IRA. Rolling into an IRA usually gives you the most investment choices and the lowest fees. Avoid cashing out: you will owe tax plus a 10% early-withdrawal penalty if you are under 59 and a half.
Does the employer match count toward my $24,500 limit?
No. The $24,500 elective deferral limit covers only your own contributions. Employer matches count toward a separate, much higher total limit ($70,000 for 2026 including all contributions), so the match never crowds out your own contributions.
What fees should I watch for?
Expense ratios on the funds inside your 401(k) are the big one: the difference between a 0.05% index fund and a 1% actively managed fund can cost six figures over a career. Check your plan's fund lineup and prefer low-cost index options when available.