Quick answer
To project your 401(k), enter your current balance, monthly contribution (employee + employer match combined), expected return, and retirement age into the calculator. Use 6–7% as a long-run return assumption for a diversified stock-heavy portfolio, and lower it to 5–6% if you are within 10 years of retirement.
What a consistent contribution grows to
| Monthly contribution | Over 20 years (7%) | Over 30 years (7%) | Over 35 years (7%) |
|---|---|---|---|
| $500/mo | $262,000 | $567,000 | $865,000 |
| $1,000/mo | $524,000 | $1,133,000 | $1,731,000 |
| $1,500/mo | $787,000 | $1,700,000 | $2,596,000 |
| $2,000/mo | $1,049,000 | $2,267,000 | $3,461,000 |
Assumes contributions start from $0 at a 7% average annual return. Actual results depend on investment choices, fees, and market performance. Add your existing balance on top of these figures.
The employer match: free money with conditions
Contribute enough to get the full match
A common match is 50% of contributions up to 6% of salary. On an $80,000 salary, that is $2,400 in free money per year — only if you contribute at least 6%.
Check the vesting schedule
Employer contributions often vest over 3–6 years. If you leave before fully vested, you may forfeit part of the match. This is a real cost of changing jobs early in your career.
Include it in your projection
When entering monthly contributions in the calculator, add your employee contribution plus the expected monthly match to get a complete growth picture.
2025 contribution limits
| Type | Under 50 | Age 50+ (with catch-up) |
|---|---|---|
| Employee contribution | $23,500 | $31,000 |
| Total (including employer) | $70,000 | $77,500 |
| Traditional IRA | $7,000 | $8,000 |
| Roth IRA | $7,000 | $8,000 |
Limits are indexed to inflation and may increase in future years. Verify current limits at irs.gov.
See your 401(k) at retirement
Enter your current balance and contributions to project your balance at any retirement age, with or without inflation.
What the 401(k) calculator does not show
The retirement calculator projects total portfolio balance — it does not break out your 401(k) from other accounts separately. If you have both a 401(k) and a taxable brokerage account, combine the balances and contributions to get your full picture.
The calculator also uses a single average return throughout the accumulation phase. Real returns vary year to year. The what-if scenario panel lets you stress-test with a 2% return reduction to see how your plan holds up if markets underperform for a period.
Tax treatment matters too. A traditional 401(k) reduces your taxable income now but withdrawals are taxed as ordinary income later. A Roth 401(k) offers no upfront deduction but tax-free withdrawals in retirement. The long-run difference depends on your current vs. expected future tax rate.