How the 401(k) Growth Calculator works.
Future value = current balance compounded annually plus yearly employee and employer deposits compounded at the entered net rateEnter values in the units named in each field. The calculator retains precision during the calculation and rounds displayed currency and measurements for readability.
Worked example for the 401(k) Growth Calculator.
For this 401(k) Growth Calculator example, with Current balance (USD): 25000; Employee contribution per year (USD): 10000; Employer contribution per year (USD): 3000; Annual return after fees (%): 6; Years: 20, the calculator returns $558,391.07. 2026 planning assumptions: end-of-year contributions and annual compounding after fees.
What this calculation uses
Future value = current balance compounded annually plus yearly employee and employer deposits compounded at the entered net rate. Contributions are modeled at year end; use a return assumption after investment fees.
What the five inputs represent
Enter the current account balance, annual employee contribution, annual employer contribution, expected annual return after investment fees, and whole years to project. The two contribution amounts are modeled separately but deposited on the same year-end schedule. Use one consistent currency for all amounts; the currency sign is display formatting and does not convert money.
How annual compounding and deposits work
The current balance compounds for every modeled year. Employee and employer contributions are added together and treated as one deposit at the end of each year, so a new deposit begins earning the entered return in the following year. With a nonzero rate, the page uses a future-value annuity factor for those deposits; at exactly 0%, it adds contributions without growth to avoid dividing by zero.
Worked example
With a $25,000 starting balance, $10,000 employee contribution, $3,000 employer contribution, 6% annual return after fees, and 20 years, this model produces $558,391.07. Of the cash entered, $25,000 is the starting amount and $260,000 is contributed over 20 years; the remaining modeled amount comes from the assumed annual compounding sequence. It is a scenario result, not a forecast or guarantee.
How to interpret a scenario
These results are planning estimates only. Compare scenarios by changing one assumption at a time: contribution amount, employer amount, return, or years. At 0% return, the result shows only the starting balance plus deposits. A negative return reduces the projected value, while a higher positive assumption compounds more strongly over longer periods. Do not choose an investment or contribution solely from one ending balance.
2026 contribution-limit assumption
The employee contribution field is capped at $24,500 because that is the explicit 2026 elective-deferral planning assumption stated on this page. That cap is not a current-limit determination and does not include every catch-up category or plan rule. Employer contributions are shown separately and are not tested against a complete annual-additions limit. Verify the current IRS limits, your age-based eligibility, and your plan documents before contributing.
What the projection leaves out
The model does not include payroll-by-payroll deposit timing, contribution changes, vesting, changing IRS limits, catch-up contributions, investment volatility, sequence of returns, inflation, taxes, required distributions, loans, withdrawals, rollovers, employer-match formulas, plan eligibility, asset allocation, or fees beyond assuming your entered return is already net of fees. Years must be whole because this model applies one annual deposit and compounding step per year.
What this calculator does not include.
Contributions are modeled at year end; use a return assumption after investment fees. This calculator is an arithmetic estimate, not a quote, contract, fit guarantee, tax return, benefit determination, route service, or recommendation. Current terms, product specifications, rules, and personal circumstances can change the real outcome.
Reference guidance and methodology.
401(k) Growth Calculator questions.
When are contributions added in this model?
Employee and employer annual amounts are combined and deposited at the end of each modeled year. Real payroll deposits usually occur more often and can produce a different result.
What happens when the return is 0%?
The page adds the starting balance and all annual deposits without growth. It uses this direct case instead of dividing by a zero rate.
Can I enter a negative return?
Yes, down to the displayed lower boundary. A negative assumption reduces the modeled balance and can be useful for stress testing, but it is not a market forecast.
Why is the employee contribution capped at $24,500?
That is the page’s stated 2026 elective-deferral planning assumption. Verify current IRS limits, catch-up eligibility, and your plan rules before contributing.
Does the result include taxes, inflation, or withdrawals?
No. It is a nominal annual-compounding scenario and does not model taxes, inflation, loans, withdrawals, required distributions, or changing contribution and return patterns.
Does FigureNest send my retirement inputs anywhere?
No. The calculation runs locally in the browser and does not use a calculation service.