A 401(k) is the most powerful retirement account most Americans will ever touch — not because of its name, but because of three forces stacking together: your own tax-advantaged contributions, free money from your employer's match, and decades of compound growth. This calculator combines all three so you can see where you are headed.
The biggest mistake people make is leaving the match on the table. A typical employer matches 50% of your contributions up to 6% of your salary — that is an instant 50% return on the matched portion, before the market does anything. At minimum, always contribute enough to capture the full match; it is the only guaranteed return in investing.
For 2026, the IRS lets employees contribute up to $23,500 in elective deferrals ($31,250 if you are 50 or older, thanks to catch-up contributions). If your projection looks short, bumping your contribution rate by even 1% per year compounds into six figures over a career.
How to use the 401(k) Calculator
- Enter your age and target retirement age — time is the biggest lever in the calculation.
- Add your current 401(k) balance and your annual salary.
- Set your contribution rate and your employer's match formula — check your benefits portal if unsure.
- Choose an expected annual return (7% is the long-run stock-market average before inflation).
- Click Calculate Projection for your future balance, split into contributions, employer match, and growth.
Tips to grow your 401(k) faster
- Never contribute less than the full employer match — it is an instant 25–100% return.
- Raise your rate 1% every year; you will not miss it, and it compounds enormously.
- Keep fees under 0.2% — a 1% fee can eat a quarter of your balance over 35 years.
- Do not cash out when changing jobs — roll it into an IRA or your new plan.
Traditional vs Roth 401(k)
Traditional 401(k) contributions are pre-tax: they shrink today's tax bill, and you pay income tax when you withdraw in retirement. Roth 401(k) contributions are after-tax: no deduction now, but growth and withdrawals are tax-free later. Early-career savers usually prefer Roth; high earners generally prefer traditional.
Frequently asked questions
What is the 401(k) contribution limit for 2026?
For 2026, employees can contribute up to $23,500. Workers age 50 and over can add a $7,750 catch-up contribution, for a total of $31,250.
How does employer matching work in a 401(k)?
A common formula is 50% of your contributions up to 6% of your salary. That means contributing 6% of pay earns an extra 3% of pay from your employer — free money.
How much should I contribute to my 401(k)?
At minimum, contribute enough to get the full employer match. Planners typically recommend 15% of gross pay (including the match) for a comfortable retirement.
Is a 401(k) or Roth 401(k) better?
Traditional contributions are pre-tax; Roth contributions are after-tax but grow and withdraw tax-free. Higher earners now often prefer traditional, while younger or lower earners may prefer Roth.