401(k) Retirement Calculator

Each year, your contribution is calculated as a percentage of your salary. Your employer then matches a percentage of that contribution, up to a cap — for example, a common structure is a 50% match on contributions up to 6% of your salary.

Your account balance grows each year based on your expected investment return, and your salary (and therefore your contributions) increases annually based on your expected salary growth rate. For simplicity, this calculator applies a full year of growth before adding that year's contributions, which slightly understates the effect of contributions made earlier in the year.

The projected balance at retirement is the sum of your starting balance, every year's investment growth, and every year's employee and employer contributions.

To estimate monthly income in retirement, this calculator applies the widely-cited "4% rule" — a planning heuristic suggesting you can withdraw about 4% of your balance per year with a low risk of running out of money over a long retirement. It's a rule of thumb, not a guarantee.

The Social Security figure is a rough estimate using the SSA's actual benefit formula (the 90%/32%/15% bend-point formula applied to your average indexed monthly earnings), but it approximates your lifetime average earnings using just your current salary — a real SSA estimate uses your highest 35 years of actual indexed earnings. Treat this as a ballpark, and check ssa.gov for your real estimate.

A 30-year-old with a $20,000 starting balance and a $70,000 salary, contributing 10% of salary with a 50% employer match up to 6% of salary, assuming 3% annual salary growth and a 7% annual investment return, would have a projected balance of about $2,002,300 at age 65.

Of that total, about $423,235 comes from the employee's own contributions, $126,970 from employer matching, and roughly $1,432,095 from investment growth — a reminder of how much compounding over decades can outweigh the contributions themselves.