About this tool
Simple interest is charged only on the original amount. It is common in short-term loans, bonds and basic school math problems.
How to use Simple Interest Calculator
- Enter the principal amount.
- Add the interest rate per year and the time in years.
- Press Calculate to see the interest and total amount.
Frequently asked questions
What is the simple interest formula?
SI = P × R × T ÷ 100, with P as principal, R as yearly rate in percent and T as time in years.
How is it different from compound interest?
Simple interest never earns interest on interest, so growth is linear instead of accelerating.