Simple Interest Calculator
Compute simple interest and maturity amount.
About this tool
Some loans and homework problems use simple interest instead of compounding. This free simple interest calculator computes interest and total payable from principal, rate, and time. Enter the three inputs, get results locally, and double-check textbook or short-term loan scenarios quickly.
How to use
- Enter the principal amount.
- Enter the annual interest rate and time period.
- Calculate interest and total amount payable.
- Adjust inputs to compare different short-term scenarios.
Frequently asked questions
Simple interest applies only to the original principal. Compound interest earns interest on prior interest—use the compound tool for that.