About the 401(k) Calculator
This 401(k) calculator projects how much your workplace retirement account could be worth by the time you retire. It models your own payroll contributions as a percentage of salary, your employer’s matching formula, yearly raises and a steady investment return, then shows the balance in both future dollars and today’s purchasing power.
Use it to see what a 1% or 2% increase in your contribution rate is worth over a career, to check whether you are capturing the full employer match, or to estimate the income your 401(k) could support using the 4% withdrawal guideline. It works for traditional and Roth 401(k) accounts alike, because both grow the same way before taxes on withdrawal.
Contributions are made monthly and compound monthly. Your own deferrals can be capped at the 2026 IRS elective deferral limit of $24,500 (plus the $8,000 catch-up from age 50, or $11,250 at ages 60–63); the limit is held flat in the projection, which is conservative because the IRS raises it with inflation.
With the default inputs, the 401(k) balance at retirement is $2,920,824.72. Change any value above to recalculate instantly.
How to use the 401(k) calculator
- 1Enter your age, planned retirement age and current salary.
- 2Set the percentage of pay you contribute and your expected yearly raise.
- 3Enter your employer’s match formula, e.g. 50% up to 6% of salary.
- 4Add your current 401(k) balance and an expected long-term return.
- 5Read the projected balance and the today’s-dollars value, then try a higher contribution rate.
Formula and method
The balance is simulated month by month. Each month the existing balance earns one-twelfth of the annual return, then one-twelfth of the year’s employee and employer contributions is added. Salary rises by the raise percentage at the start of each year, so contributions grow with pay.
The employer match equals the match rate multiplied by your contribution, but only up to the “match up to” percentage of salary — for example 50% of contributions up to 6% of pay is worth at most 3% of salary. The today’s-dollars figure divides the final balance by (1 + inflation) raised to the number of years, so you can compare it with prices today.
- B
- 401(k) balance
- r
- Expected annual return
- S
- Salary for the year (grows with raises)
- c
- Your contribution rate
- m
- Employer match rate
- L
- Match limit as a share of salary
Worked examples
Age 30, $85k salary, 10% contribution, 50% match up to 6%
You contribute $8,500 in year one and the employer adds $2,550 (50% of the first 6% of pay). With 3% raises and a 7% return over 35 years, the account grows to about $2.92 million, of which roughly $668,000 is contributions and the rest investment growth.
Age 45, no raises, 100% match up to 4%
Contributing 6% of a $60,000 salary is $3,600 a year and the employer matches dollar-for-dollar up to 4% of pay, adding $2,400. Over 20 years at 6%, the existing $100,000 plus $500 a month of contributions grows to about $562,000.
High earner capped at the IRS limit
Fifteen percent of $300,000 would be $45,000, but employee deferrals are capped at the 2026 limit of $24,500. The match is 50% of contributions up to 6% of salary ($18,000), so the employer adds $9,000 a year.
Frequently asked questions
How much should I contribute to my 401(k)?+
At minimum contribute enough to receive the full employer match, since that is an immediate return on your money. Many planners suggest saving 15% of gross pay for retirement in total, including the employer match.
What is the 401(k) contribution limit for 2026?+
For 2026 the IRS elective deferral limit is $24,500. Workers aged 50 or older can add an $8,000 catch-up, and those aged 60 to 63 can use a higher “super catch-up” of $11,250 instead if their plan allows it.
Do high earners have to make catch-up contributions as Roth?+
Starting in 2026, if your FICA wages from that employer exceeded $150,000 in the prior year (2025 wages, a threshold the IRS indexes), SECURE 2.0 requires your catch-up contributions to go in as Roth (after-tax). The dollar limits are unchanged; only the tax treatment differs.
Does the employer match count toward the $24,500 limit?+
No. The $24,500 limit applies only to your own deferrals. Employer matching and profit-sharing contributions fall under the separate total annual additions limit, which is $72,000 for 2026 (not counting catch-up contributions) or 100% of your pay if less.
What return should I assume for a 401(k)?+
A diversified stock-heavy portfolio has historically returned around 7%–10% a year before inflation, but future returns are uncertain. Using 6%–7% gives a more conservative plan, and lower figures make sense as you shift to bonds.
Is a Roth 401(k) or traditional 401(k) better?+
A traditional 401(k) lowers taxes now and taxes withdrawals later, while a Roth 401(k) is taxed now and withdrawn tax-free. Roth tends to win if you expect a higher tax rate in retirement; the projected balance is the same either way.
What happens to my match if I leave my job?+
Your own contributions are always yours, but employer contributions may follow a vesting schedule of up to three years (cliff) or six years (graded). Unvested match is forfeited when you leave.
Results are estimates for educational purposes and are not financial advice. Rates, fees and terms vary — confirm with your lender or a licensed advisor before making decisions.