401k Growth Calculator

• How much will my 401k be worth?

  It depends on five inputs: your current balance, your annual contributions, any employer match, your expected return, and the years left until retirement. For example, a 30-year-old with $25,000 saved, contributing 10% of a $70,000 salary with a 50%-up-to-6% match at a 7% return, reaches roughly $1.4 million by 65 — of which about $1.0 million is investment growth and only $300,000 is money contributed. That is why starting early matters more than the exact amount: waiting until 40 to begin, all else equal, more than halves the result to about $620,000. One caveat: this models returns as a steady average, while real markets are volatile year to year; figures are pre-tax nominal dollars that inflation erodes, and a 1% higher fee can cut a lifetime balance by tens of percent.

• How to calculate 401k growth?

  Compound your current balance forward at your expected annual return, then add each year's employee and employer contributions and compound each of those for the years remaining until retirement. Summed together, that is your projected future value. For example, $50,000 today at 7% for 25 years grows to about $271,000 on its own; adding $10,000 of contributions a year compounds to roughly $633,000 more, for about $904,000 total. The longer the horizon, the more the growth component dominates, because early contributions have the most time to compound. This calculator runs that year-by-year projection for you. One caveat: the result assumes a constant return, but real markets fluctuate, and the figures are pre-tax nominal dollars — inflation reduces their real purchasing power, and a traditional balance is taxed as ordinary income when withdrawn.

• How to calculate rate of return on a 401k?

  To isolate investment performance from the money you added, subtract your contributions (and any match) over the period from the ending balance to find the pure investment gain, divide that by the starting balance, and annualise over the number of years. For a rough single-year figure: (ending balance − contributions − starting balance) ÷ starting balance. For example, if you began the year at $100,000, contributed $10,000, and ended at $118,000, the $8,000 gain on the $100,000 base is about an 8% return. For multi-year accuracy, a money-weighted return (IRR) accounts for the timing of each contribution. One caveat: comparing your 'return' to an index without stripping out contributions overstates performance, because new money inflates the balance regardless of how the investments actually did — always separate the two before judging your funds.

• How much should I have in my 401k by my age?

  A widely cited benchmark from Fidelity suggests having about 1× your salary saved by 30, 3× by 40, 6× by 50, and 8–10× by 67. On a $60,000 salary that is roughly $60,000 by 30, $180,000 by 40, and $360,000 by 50. These are rough guides, not rules — they assume broad averages for returns, retirement age, and spending, so your own number depends on when you want to retire and your other income sources. What matters far more than hitting an exact multiple is your savings rate: aiming for about 15% of gross pay including any match, consistently, over a career. One caveat: if you are behind, the age-50 catch-up adds $8,000 a year (or $11,250 at ages 60–63) to help close the gap in your final working decade.

• What will my 401k be worth in 20 or 30 years?

  Enter your current balance, annual contribution, and expected return, and the calculator projects the balance year by year to your chosen horizon. Because growth compounds, a longer horizon produces disproportionately more: a 30-year projection usually yields far more than twice a 15-year one, since the later years grow a much larger base. For example, $500 a month at 7% reaches about $260,000 over 20 years but roughly $567,000 over 30 — the extra decade more than doubles it. The two biggest levers are how early you start and how consistently you contribute. One caveat: 7% is a long-run average, not a promise — real returns vary year to year and are never guaranteed — and the projection is in pre-tax nominal dollars, so inflation reduces what the final balance will actually buy.

• IRS-accurate formulas

  Uses the current IRS contribution limits, penalty rules and RMD tables — updated for 2026.

• 100% free, no login

  No signup, no email wall, no paywall. Every calculator is fully usable on first visit.

• Your data never leaves your browser

  Every calculation runs client-side in JavaScript. Nothing is sent to a server or stored.

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