401(k) & Roth IRA growth
The giant number is the future balance. Employer match is added each year, capped as a percent of salary.
Where the balance comes from
Deposits, match, and market growth stacked over time.
End mix
How much of the final number is money you never deposited.
How this 401(k) and Roth chart works
We add your contribution and any employer match each year, then apply a constant annual return. Match is modeled as a simple percent of your contribution up to a cap you type — real plans have vesting, true-up, and compensation limits this page does not copy. The ending balance is the account value in future dollars at a smooth return, not a guarantee.
The math of compounding is the same in a traditional 401(k) and a Roth IRA. Tax treatment is not. A traditional 401(k) often reduces taxable pay now; a Roth is usually funded with after-tax money and may be withdrawn tax-free in retirement if IRS rules are met. This calculator shows growth of the account, not your after-tax spending power in retirement.
Capture the full match before you optimize Roth versus traditional. Then look at take-home pay to see what a higher deferral does to this month’s deposit, and at FIRE years if you care about a portfolio target rather than a year-N balance.
FAQ
Is the employer match included?
Yes, using the match rate and cap you enter. If your plan matches 50% of the first 6% of pay, set the fields to that. Vesting is not modeled — money you forfeit if you leave early is not subtracted.
Why is the return a straight line?
A constant rate is easier to read than a random market. Real years cluster: some are large losses. Treat the ending balance as a planning midpoint, not a promise.
Does this respect IRS contribution limits?
You can type any monthly amount. Compare it with the current-year employee deferral limit and any catch-up that applies to you. The tool will not stop you from entering an illegal number.
Take-home payFIRE yearsMatch & compounding guide