401K Calculator

This tool projects a future 401(k) balance from a starting balance, salary, employee contribution rate, employer match terms, expected annual return, salary growth, and years until retirement. It separates the projected balance into your contributions, employer match, and estimated investment growth so you can see what drives the result. Use it for retirement accumulation and employer-match planning; it does not estimate retirement payouts, withdrawals, Social Security income, or how long a retirement balance will last.

1. Enter your current 401(k) balance and annual salary.
2. Enter the percentage of salary you contribute.
3. Describe your employer match as a match rate and the maximum percentage of salary that can receive that match.
4. Choose the annual return and salary growth assumptions you want to test.
5. Enter the number of years until retirement, then calculate and review the total and year-by-year projection. If you plan by age, subtract your current age from your intended retirement age and enter that number of years.

The model works month by month. Your annual return is converted to an equivalent monthly growth rate. Employee and employer contributions are added at the end of each month. Salary changes once per year using the annual salary-growth assumption.

Because every input is user-entered, the model can be used without embedding current contribution limits or tax rules that may change over time.

With a $50,000 starting balance, $80,000 salary, 8% employee contribution, 50% employer match up to 6% of salary, 7% annual return, 2% annual salary growth, and 30 years, this model projects about $1.43 million. Of that amount, roughly $259,636 comes from employee contributions, $97,363 from employer matching, and about $1.03 million from investment growth. The example is a mathematical illustration, not a forecast.

• The calculator does not enforce current IRS contribution limits, catch-up provisions, taxes, withdrawal rules, required distributions, plan eligibility, vesting schedules, or employer-specific restrictions.
• Investment returns are assumed to be constant at the annual rate you enter. Real market returns vary.
• Salary growth changes once per year. Real pay can change irregularly.
• Contributions are modeled monthly and added at the end of each month.
• Fees and inflation are not modeled separately.
• Results are educational estimates and are not financial, tax, or investment advice.

Does this calculator use the current 401(k) contribution limit?

No. It intentionally does not hard-code current limits. The calculation uses the contribution percentage you enter, which keeps the projection independent from changing annual rules.

How is the employer match calculated?

The match applies your employer match rate only to the portion of salary up to the match cap you enter. If your contribution rate is below the cap, only your actual contribution rate is matched.

Why can investment growth be much larger than contributions?

Over long periods, earlier balances and contributions can compound repeatedly. The result depends strongly on the return and time assumptions you choose.

Is the projected balance guaranteed?

No. It is a scenario based on fixed assumptions. Actual returns, salary, contributions, employer terms, fees, taxes, and plan rules can differ.

Can I use this 401(k) calculator by age?

Yes. Subtract your current age from the age when you plan to retire, then enter that result as years until retirement. This version keeps the input as years so the projection stays simple and transparent.

Does it calculate 401(k) withdrawals, payouts, Social Security, or catch-up contributions?

No. Those are different planning jobs. This calculator focuses on accumulation before retirement using the contribution percentage and employer-match assumptions you enter, and it does not hard-code changing catch-up rules.