Interest Calculator

Compare simple and compound interest using your own principal, rate, term, compounding frequency, and optional recurring contributions.

Interest type

Starting principal

Annual rate (%)

Years

Compounding

Monthly contribution

—Final balance

—Interest earned

—Total contributed

—Effective annual yield

—Last month interest

How to use this Interest Calculator

Calculate simple or compound interest, final balance, and effective annual yield. Enter your values above and the result is calculated directly in your browser. No account is required.

Fast answer, clear inputs

This tool is built around one job: give the answer quickly without forcing a signup or hiding the result. Related tools are linked nearby when the next calculation or conversion is useful.