How the 401(k) Calculator works
A workplace plan can combine employee deferrals, employer contributions, and investment growth. The match calculation applies the stated match rate only up to the entered salary percentage.
Method: Monthly deposits combine salary deferrals with employer match, then compound with the starting balance.
Inputs to review
- Annual salary: Use a realistic current value and test a conservative alternative.
- Employee contribution: Use a realistic current value and test a conservative alternative.
- Employer match rate: Use a realistic current value and test a conservative alternative.
- Match applies up to: Use a realistic current value and test a conservative alternative.
- Current 401(k) balance: Use a realistic current value and test a conservative alternative.
- Estimated annual return: Use a realistic current value and test a conservative alternative.
- Years contributing: Use a realistic current value and test a conservative alternative.
How to interpret the result
Compare your contribution with the plan's full-match threshold and current IRS limits. Vesting, plan fees, fund choices, and whether contributions are traditional or Roth affect the real outcome.
Assumptions and limitations
The tool does not enforce annual legal limits or age-based catch-up rules because those amounts change. Confirm the current limit with the IRS and your plan administrator.
Recalculate when rates, balances, income, goals, or time horizons change. A useful estimate is a range built from several plausible scenarios, not a single precise-looking number.