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Retirement / 401(k) Calculator
See what your 401(k) could be worth at retirement. Add your current balance, monthly contribution and employer match — the projection updates instantly as you type, with compound growth calculated month by month.
✓ Free — no sign-up✓ Employer match included✓ Compounded monthly✓ Nothing is saved
How it works
This calculator grows your money in monthly steps. Every month, your contribution and your employer's match are added, and the whole balance earns 1/12 of your expected annual return. Over decades, that compounding — earning returns on earlier returns — is usually the largest part of the final balance.
1 Start with todayYour current 401(k) balance begins compounding immediately, even if you never added another dollar.
2 Add contributions + matchEach month we add your contribution plus the employer match. A 50% match on $500 adds a free $250 every month.
3 Compound monthlyThe balance is multiplied by (1 + annual return ÷ 12) each month until your retirement age.
Future value = Balance × (1 + r)n + Monthly total × [ ((1 + r)n − 1) ÷ r ] · r = annual return ÷ 12, n = months to retirement
Worked example: Age 30 → 65, $10,000 saved, $500/month from you + 50% match ($250) = $750/month, at 7% compounded monthly gives $1,465,852.47 — of which $325,000 is money put in and $1,140,852.47 is investment growth.
Frequently asked questions
How is my 401(k) projection calculated?
Your current balance and monthly contributions (plus employer match) are compounded monthly at your expected annual return until your retirement age. Contributions are added at the end of each month.
What is an employer 401(k) match?
Many employers match part of what you contribute — for example 50% of your contribution, often up to 3–6% of your salary. In this calculator the match is entered as a percentage of your contribution, so 50% on $500/month means your employer adds $250/month. It is essentially extra pay for retirement, so contributing at least enough to get the full match is usually the first priority.
What annual return should I assume?
Long-term US stock market returns have averaged roughly 10% before inflation and about 7% after inflation historically, but returns vary a lot year to year and past performance does not guarantee future results. Try 5% for a conservative view, 7% for moderate, and 9% for aggressive to see a range.
Does this calculator include taxes, fees or inflation?
No. It shows a gross projection before taxes, plan fees and inflation, so you can compare contribution and match scenarios clearly. A traditional 401(k) is taxed when you withdraw in retirement; a Roth 401(k) is taxed upfront instead.
How much should I contribute to my 401(k)?
At a minimum, contribute enough to capture your full employer match — otherwise you are leaving money on the table. Beyond that, many savers aim for 10–15% of income including the match, adjusted for debts, other goals and your age. Use the slider above to see how even $100/month more changes the outcome over 30+ years.
What happens if I start later or retire earlier?
Time is the biggest lever. Starting 10 years later means far fewer compounding periods, so the same monthly amount ends much smaller. Try moving your current age or retirement age above and watch the growth portion shrink or expand — that gap is compounding at work.