Calculator

Compound Interest Calculator

Estimate how a principal grows when interest is added repeatedly over time.

Calculate compound interest

Amounts are shown in the same currency or unit as the principal. This calculator assumes a fixed rate and no deposits or withdrawals.

Informational estimate: Actual results may differ due to rate changes, fees, taxes, contribution timing, rounding, and institution-specific rules. Confirm applicable terms before making a financial decision.

How compound interest works

Compound interest is calculated on the principal and on interest already added. The calculator uses the formula A = P(1 + r/n)nt, where P is principal, r is the annual rate as a decimal, n is the number of compounding periods per year, and t is time in years.

More frequent compounding can produce a higher final amount when the principal, rate, and time remain the same. This calculator does not include regular contributions.