401(k) Calculator

What each input means

• Annual salary — Base used to compute dollar contributions from the percentages below.
• Your contribution (%) + employer match (%) — Combined into one annual cash flow: annual contribution = salary × (your% + match%) ÷ 100.
• Expected annual return (%) — Constant growth rate r each year.
• Years to invest — Number of compounding periods (same as “years” in the formula below).

Formula used

Future value of a constant end-of-year contribution stream:

FV ≈ PMT × ((1 + r)ⁿ − 1) ÷ r, with PMT = annual contribution, r = return ÷ 100, n = years. If return is 0, FV = PMT × n.

Ignores contribution limits, vesting schedules, catch-up, fees, taxes on withdrawal, and irregular raises.