This 401(k) calculator projects your retirement balance from the things you control — contribution rate, employer match, salary growth — plus expected returns. See the final balance broken into your contributions, your employer’s match, and investment growth.

Balance at Retirement–
Your Contributions–
Employer Match–
Investment Growth–

How a 401(k) Grows

A 401(k) grows from three sources: your contributions (pre-tax, straight from salary), your employer's match (an instant 50–100% return on the matched portion — the closest thing to free money in finance), and investment growth compounding tax-deferred for decades. This calculator models all three year by year. For the drawdown side of retirement, see the Retirement Calculator; this page is in our Finance Calculators collection.

Worked Example (Verified)

Balance $50,000, salary $80,000, contributing 10%, employer matches 50% of the first 6% (an extra 3% of salary), 2% annual raises, 7% returns, 30 years:

  • Final balance: $1,671,660
  • Your contributions: $324,545
  • Employer match: $97,363
  • Investment growth: $1,199,752 — growth ends up contributing more than both contribution streams combined. That is compounding over 30 years.

Try cutting the return to 5% or the horizon to 20 years above — the growth card is where the damage shows. Time is the dominant ingredient, which is why starting early beats contributing heroically late.

The Rules That Matter Most

  • Always capture the full match. Contributing less than the match cap is declining part of your pay.
  • Contribution limits (2025): $23,500/year if under 50; $31,000 with the catch-up at 50+. (Employer contributions have a separate, higher combined limit.)
  • Traditional vs Roth 401(k): traditional is pre-tax now, taxed at withdrawal; Roth is taxed now, tax-free later. Lower bracket today → Roth often wins; peak earning years → traditional often wins.
  • Fees compound too: a 1% annual fee difference can cost six figures over 30 years — the return input above should be net of fees.
  • Do not raid it: early withdrawals usually mean income tax plus a 10% penalty, and the lost compounding never comes back.

The growth mechanics here are exactly the Compound Interest Calculator's, fed by salary-linked contributions.

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Frequently Asked Questions

How much should I contribute to my 401(k)?

At minimum, enough to capture the full employer match. Common guidance targets 12–15% of income (including the match) for a retirement in your mid-60s, more if you started late.

What return should I assume?

Long-run US stock-market returns have averaged roughly 10% nominal (about 7% after inflation) with heavy year-to-year variation. Many planners project 6–8% nominal for a diversified portfolio. The calculator takes any rate — test pessimistic cases too.

Is the employer match really that important?

In the example above the match adds $97,363 of contributions that grow to several times that. A 50% match is an instant 50% return before the market does anything.

What happens to my 401(k) if I change jobs?

It stays yours. You can leave it, roll it into an IRA, or roll it into the new employer's plan — each with different fee and investment implications, and no tax if done as a direct rollover.

Does this calculator include taxes?

No — it projects the pre-tax balance. Traditional 401(k) withdrawals are taxed as income in retirement; Roth withdrawals are tax-free. Your eventual spendable amount depends on your future tax bracket.

Is this 401k calculator free?

Yes — free, instant, no sign-up. Projections are estimates based on your inputs, not financial advice.