About this calculator
Simple interest is I = P × R × T ÷ 100, where P is the principal, R the yearly rate in percent and T the time in years. Unlike compound interest, the interest itself never earns interest.
Worked example
10,000 × 5 × 3 ÷ 100 = 1,500 of interest, for a total of 11,500 after 3 years.
How to use the simple interest calculator
- Enter the principal.
- Enter the rate (per year).
- Enter the time.
- Read the result — it updates as you type.
Frequently asked questions
What is the simple interest on 10,000 at 5% for 3 years?
10,000 × 5 × 3 ÷ 100 = 1,500, for a total of 11,500.
Is simple interest better than compound interest?
For a borrower, simple interest costs less. For a saver, compound interest earns more.