401(k) Calculator
Estimate future 401(k) savings including employee contributions and employer match.
Educational estimate only. This is not financial, investment, tax, legal or lending advice, a quote or a guarantee. Read the disclaimer.
Your inputs
Illustrative growth by year.
How this calculator works
P is the starting balance, C is the contribution at each month-end, r is the entered annual percentage divided by 100 and then 12, and n is years × 12. The rate is treated as a nominal annual rate, not APY or an effective annual return. Returns are constant in this illustration; no taxes, fees, inflation, withdrawals or market volatility are modeled. Fractional years use fractional exponents; the chart shows completed years only. Years is retirement age minus current age. Monthly contribution C = annual salary × (employee percentage + employer percentage) ÷ 100 ÷ 12. Salary and percentages remain constant. Employer percentage means the actual contribution as a percentage of salary, not the percentage of employee contributions matched. Enter the effective employer amount yourself. The model does not enforce tax-year contribution limits, match eligibility, vesting, catch-up rules, salary growth or tax treatment; verify these with your plan.
Dollar results are in USD and generally rounded to the nearest whole dollar; salary equivalents and percentage outputs use two decimal places. Calculations retain JavaScript floating-point precision between steps rather than rounding every payment to cents. Displayed components may not sum exactly to displayed totals. Payoff times use whole monthly payment periods. Defaults are examples, not current rates or recommendations.
Full methodology · About the publisher and corrections
Content and calculation checks: October 12, 2026. Educational estimates; no independent professional certification is claimed.
Worked example: $90,000 salary with 8% + 4%
At age 35, with an $80,000 current balance, $90,000 salary, an 8% employee contribution, a 4% employer contribution and an illustrative 7% annual return through age 67, the model projects about $2.03 million.
Over that period, modeled employee contributions total about $230,400 and employer contributions about $115,200. The calculation assumes salary and contribution percentages do not change and does not enforce annual contribution limits.
Practical guide
Use your actual plan rules
- Enter the employer contribution you realistically expect, not an advertised maximum you may not qualify for.
- Check vesting, eligibility, contribution limits and catch-up rules in your plan documents.
- Test contribution increases separately from return assumptions.
- For savings outside a workplace plan, compare the Retirement Calculator.
How to use the result
Change one assumption at a time to compare scenarios. For example, test a lower rate, larger contribution, different term or extra payment. This makes the calculator most useful as a decision-support tool rather than a single-number answer.
Important financial decisions can depend on taxes, fees, eligibility rules, lender policies, market returns and personal circumstances that this simplified calculator does not capture.
Frequently asked questions
Is this 401(k) calculator free?
Yes. SumStride calculators are free to use and do not require an account.
Are the results exact?
No. Results are estimates based on the values you enter and the assumptions described on this page. Real-world fees, taxes, rates, policies and timing can differ.
Does SumStride save my inputs?
No account is required. The calculator runs in your browser; SumStride does not need your entered values to perform the calculation.