401(k) Calculator
Project your balance with employer match — and see the match money you're leaving on the table.
Finance tools · Free
About the 401(k) Calculator
A 401(k) is one of the best deals in the US tax code: traditional 401(k) contributions come out of your paycheck before tax, your employer often matches a slice, and the money compounds untouched until retirement. This calculator projects your balance at retirement and shows exactly how much of it came from you, from your employer, and from the market.
Enter your current balance, your salary, the percentage you contribute, your employer's match terms, and your expected return with years to retirement. The tool grows the account year by year and separates your money from free money.
Never leave the match on the table. A 50% match up to 6% of salary is an instant 50% return on that portion of your contribution (once it vests) — hard to beat anywhere else. Capturing the full match is usually one of the first priorities once you have an emergency cushion and no high-interest debt.
Small percentage changes compound hugely. Going from 5% to 10% of salary doesn't just double contributions to the start — it adds decades of growth on top. Re-run it at 5%, 10% and 15% and the gap in the projected balance is painfully obvious.
Asset allocation matters less than the habit. A modest, boring portfolio funded consistently for 30 years will beat a clever one that gets paused whenever life gets expensive. Automate the contribution, raise it every time you get a salary bump, and let time do the heavy lifting. This is general education for US workplace plans, not financial advice.
How to use it
- Enter your current balance. The account value today, if you've already started.
- Enter your annual salary. Used to convert your contribution percentage into dollars.
- Set your contribution percentage. At minimum, enough to capture the full employer match.
- Set the employer match terms. Match percentage and how much of your salary it applies to.
- Set your return and timeline. ~7% and 30 years is a common planning assumption.
- Read your projected balance. See your contributions, employer match and growth broken out.
Frequently asked questions
How does the 401(k) calculator work out the employer match?
Your employer's yearly contribution is salary × the lower of your contribution % and the match cap % × the match rate. With the defaults ($80,000 salary, 6% contribution, 50% match up to 6%) you put in $4,800 a year and your employer adds $2,400. Starting from $10,000 at 7% for 30 years, that projects to about $756,000, of which roughly $530,000 is investment growth.
What does 'leaving match money behind' mean in the 401(k) calculator?
If your contribution percentage is below the match cap, the calculator works out the match you're forfeiting: (match cap − your %) × salary × match rate. For example, contributing 3% with the default 50%-up-to-6% match leaves $1,200 a year unclaimed. Raising your contribution to the cap removes that gap.
Does the 401(k) calculator enforce the IRS contribution limit?
No. It projects whatever percentage you enter, even if it exceeds the IRS annual employee deferral limit (set each year, with additional catch-up contributions allowed from age 50). Limits change each year, so check the current figure on IRS.gov. If your inputs exceed the limit, the projection will be too high.
Does the 401(k) calculator include raises, fund fees, vesting or taxes?
No. Salary stays flat, the return is constant, contributions are added once at the end of each year, and there are no fund fees, vesting schedules or taxes on withdrawal. Raises make the real result higher; fees, unvested match and taxes on pre-tax money make what you can actually spend lower.
What annual return should I use in the 401(k) calculator?
The default is 7%, a common long-term planning assumption for a stock-heavy portfolio, not a guarantee. The result is in future (nominal) dollars, so to see it in today's purchasing power, enter a return net of inflation instead. This is general education for US plans, not financial advice; confirm with a qualified professional.
Guides that use this tool
Related tools
- Compound Interest Calculator — See how your money grows with the power of compounding — visualised with charts and AI explanations. (Free, AI-powered)
- Debt Payoff Calculator — Snowball vs avalanche — let AI pick the strategy that gets you debt-free fastest. (Free, AI-powered)
- Budget Planner (50/30/20) — Build a personal budget with the proven 50/30/20 framework + AI-powered tips. (Free, AI-powered)
- Loan & Mortgage Calculator — Calculate monthly payments, total interest, and amortisation for any loan or mortgage. (Free, AI-powered)
- Credit Score Simulator — Simulate how actions impact your credit score with AI-powered explanations. (Free, AI-powered)
- Side Hustle Income Tracker — Track every dollar from your hustles — premium dashboard with charts and insights. (Premium)