Calculator

Simple Interest Calculator

Calculate interest earned or charged without compounding, plus the final amount.

Calculate simple interest

Amounts are shown in the same currency or unit as the principal.

Informational estimate: This calculation excludes compounding, fees, taxes, payment timing, and institution-specific rules. Confirm the applicable terms before making a financial decision.

How simple interest works

Simple interest is calculated only on the original principal. The formula is principal × annual rate × time in years. Unlike compound interest, previously earned interest does not earn more interest.

Use the same currency or measurement unit throughout. For months, the calculator divides the entered time by 12 before applying the annual rate.