Finance & Money
Popular
Compound Interest Calculator
Calculate investment growth with compound interest and additional contributions.
Future Value
—
Total Invested
—
Total Interest
—
Year-by-Year Breakdown
| Year | Balance | Interest | Total Interest |
|---|
Frequently Asked Questions
A = P(1 + r/n)^(nt), where A is the final amount, P is the principal, r is the annual rate as a decimal, n is the compounding frequency per year, and t is time in years. Example: $5,000 at 7% compounded monthly for 10 years: A = 5000 times (1 + 0.07/12)^120 = approximately $10,008.
Divide 72 by the annual interest rate to estimate how many years it takes to double your money. At 8% return, your money doubles in about 72 divided by 8 = 9 years. At 6%, it takes about 12 years. This is a quick mental math shortcut for investment planning.
Simple interest is calculated only on the original principal. Compound interest is calculated on the principal plus all accumulated interest, so you earn interest on your interest. Over long periods, compound interest grows exponentially while simple interest grows linearly. The longer the investment period, the greater the difference.