401(k) Projection Calculator
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Project what a 401(k) grows to by retirement, and — more usefully — how the final balance splits between what you paid in, what your employer matched, and what compounding added on top. Contributions are modelled monthly, as they actually arrive, and the employer match follows your real contribution rather than the percentage you asked for, so it stops when the annual IRS limit does. Download the year-by-year table to keep or to check against your plan statements.
How to use 401(k) Calculator
- 1
Enter your age, retirement age, current balance and salary.
- 2
Set your contribution percentage and your employer’s match — typically a percentage of the first few percent of salary.
- 3
Check the contribution limit against the current IRS figure, then read the split between contributions, match and growth.
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Frequently asked questions
How much of the final balance is growth rather than money I paid in?+
On a typical 30-plus year projection, most of it. That split is the reason this calculator reports it separately: the case for starting early is not that you contribute more, it is that early dollars have longer to compound, and no single monthly contribution figure makes that visible on its own.
How does the employer match work?+
Usually as a rate on the first slice of your salary — "50% of the first 6%" means the employer adds 50 cents per dollar you contribute, up to 6% of your pay. Contributing less than that slice leaves money on the table; contributing more earns no additional match, though it still grows tax-deferred.
Why is the contribution limit something I have to enter?+
Because the IRS elective-deferral cap changes almost every January, along with the catch-up allowance at 50 and over. Baking this year’s number into the page would mean it quietly went wrong at the next change, on a projection people plan around. Keeping it as a field you can check is honest about a figure that has a shelf life.
Is a 7% return realistic?+
It is a common long-run assumption for a stock-heavy portfolio before inflation, and no market delivers it smoothly — real returns arrive as a sequence of good and terrible years, and the order matters near retirement. Treat this as a straight-line projection, not a forecast, and try it again a few points lower.
Does this account for inflation and fees?+
No. The result is in future dollars, so it buys less than the same number does today, and no fees are deducted. A 1% expense ratio can consume a quarter of a lifetime balance — model it by lowering the assumed return by a point, which is roughly what it costs you.