401(k) Calculator
Compounding Is the Real Employer Match
A 401(k) balance grows from two forces working together: money you and your employer put in, and the market return compounding on top of it year after year. The second force does more heavy lifting than most savers expect — over a multi-decade career, investment growth can outweigh total contributions several times over. This calculator projects your balance forward using your contribution rate, any employer match, and an assumed return, so you can see how those pieces combine before retirement day arrives.
The Formula
The projection uses the standard future value of a present balance plus a growing annuity of monthly contributions:
Where P is your current balance, PMT is your total monthly contribution (yours plus any employer match, capped at the employer's match limit if one applies), r is the annual return rate divided by 12, and n is years until retirement multiplied by 12.
Where This Calculation Matters
- Setting a contribution rate — seeing the long-run gap between, say, 6% and 10% of salary makes the tradeoff concrete instead of abstract.
- Capturing the full employer match — many plans only match contributions up to a set percentage of salary; contributing less than that limit leaves employer money on the table.
- Career and job-change decisions — comparing projected balances helps weigh a new employer's match formula against your current one.
- Sanity-checking a retirement plan — a quick projection shows whether current habits are on pace for a target balance.
How Employer Match Accelerates Growth
| Years until retirement | Projected balance |
|---|---|
| 10 | $64,906.80 |
| 20 | $195,347.50 |
| 30 | $457,489.12 |
| 40 | $984,305.02 |
Figures assume a constant monthly contribution and return rate for illustration; actual returns vary year to year.
How to Use This Calculator
- Enter your current 401(k) balance.
- Enter your own monthly contribution amount.
- Enter the employer match percentage (of your contribution) and, if the plan caps it, the match limit as a percentage of salary along with your annual salary.
- Enter the annual return rate you expect and the number of years remaining until retirement.
- Select Calculate to see your projected balance, total contributed, total employer match, and total investment growth.
Related Calculations
Compare this against a Roth IRA projection to weigh pre-tax versus tax-free growth, or use the Retirement Planner to see whether your combined savings meet your income target.