Future Value Calculator

The S&P 500 has averaged about 10% annually before inflation (roughly 7% after inflation) over the long term. Bond funds typically return 4% to 6%. A balanced portfolio might expect 6% to 8%. Use conservative estimates for planning purposes.

Compound interest earns interest on both the principal and previously accumulated interest. Simple interest only calculates interest on the original principal. Over long periods, the difference is dramatic — $10,000 at 7% for 30 years grows to about $76,000 with compounding versus $31,000 with simple interest.

This calculator shows pre-tax growth. In taxable accounts, you will owe taxes on dividends and capital gains, reducing your effective return. Tax-advantaged accounts like 401(k)s and Roth IRAs allow your investments to grow tax-free or tax-deferred.

Starting 10 years earlier can roughly double your final balance even with the same contributions. Someone investing $200 per month starting at age 25 will have about $525,000 by age 65 at 7%, while starting at 35 yields about $244,000 — less than half.