How to use this 401(k) calculator
Enter your current age and retirement age, your current balance, and your monthly contribution. Add your employer match and the cap it applies up to, your salary, your expected return, and an inflation rate. The projection updates live.
What drives your final balance
- Your contributions — the dollars you put in each month.
- Employer match — free money; always contribute enough to capture all of it.
- Compound growth — returns earning returns, which often becomes the largest share over time.
- Time — the single biggest lever; starting earlier beats contributing more later.
Frequently asked questions
How is the balance projected?
Your balance plus contributions and match compound at your expected return until retirement, then we show today's-dollars value and an estimated monthly income via the 4% rule.
How does employer match work?
Employers often match a percentage of contributions up to a salary cap (e.g. 50% up to 6%). The calculator adds it in — it's free money.
What is the 4% rule?
A rule of thumb that ~4% of your balance can be withdrawn in year one (then inflation-adjusted) with a reasonable chance of lasting ~30 years.
Why does starting early matter?
Compounding rewards time. Early dollars grow for decades and often make up a large share of the final balance.
Related calculators & guides
This calculator is for educational and planning purposes only and provides estimates, not financial advice. Investment returns are not guaranteed and involve risk of loss. See how we calculate.