Interest Calculator

Calculate simple interest and the total balance on a deposit or loan.

How this calculator works

Simple interest = principal x rate x time. It does not compound, so interest is always based on the original principal.

Frequently asked questions

How is simple interest different from compound interest?

Simple interest is earned only on the principal. Compound interest also earns interest on past interest.

Figures use 2026 US federal tax parameters. Results are estimates only.