Retirement & 401k Calculator

This free retirement calculator estimates your inflation-adjusted retirement balance, employer 401(k) match, compound growth, and sustainable monthly income. Enter your current age, retirement age, savings, salary, monthly contribution, employer match, expected return, and inflation rate.

The calculator compounds monthly contributions and employer matching contributions at the selected annual return, then adjusts the projected balance for inflation. The estimated monthly retirement income uses the 4% rule: projected real balance multiplied by 0.04 and divided by 12.

Results are estimates for educational planning, not personalized financial advice. The tool assumes a constant annual return, inflation rate, salary, contribution, and employer-match policy throughout the projection. Actual investment returns, taxes, fees, salary changes, contribution limits, and withdrawal rules may produce different results.

An employer 401(k) match is one of the most powerful wealth-building tools available to employees. When your company matches your contributions, they're essentially giving you a guaranteed return on your investment — often 50% to 100% instantly.

For example, if you earn $75,000 and contribute 6% ($4,500/year), and your employer matches 50% up to 6%, they'll add $2,250 to your account annually. Over 35 years at 7% returns, that "free money" alone grows to over $320,000. Not contributing enough to get the full match is like leaving part of your salary on the table.

The 4% rule, first published by financial advisor William Bengen in 1994, suggests that retirees can withdraw 4% of their portfolio in the first year of retirement and adjust that amount for inflation each subsequent year — with a very high probability the money will last at least 30 years.

This rule is based on historical market data using a balanced portfolio of 50% stocks and 50% bonds. While market conditions change, it remains the gold standard for retirement withdrawal planning. Our calculator uses this rule to estimate your safe monthly retirement income based on your projected savings.

Albert Einstein reportedly called compound interest "the eighth wonder of the world." In retirement planning, it's the engine that transforms modest monthly contributions into six- or seven-figure portfolios. Compound interest works by reinvesting your earnings, so those earnings generate their own earnings — creating an accelerating growth curve.

Time is the most critical factor. Starting at age 25 instead of 35 with just $500/month can mean an extra $600,000+ at retirement. That's the exponential nature of compounding — the later years produce the most dramatic growth. Our chart above visualizes exactly how your money accelerates over time.