Simple Interest Calculator
Calculate simple interest and the total amount for any principal, rate and time period.
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How to use the Simple Interest Calculator
- 1
Enter the principal amount and the annual interest rate.
- 2
Enter the time period in years, months or days.
- 3
Read the interest, the total amount and how it compares with compound interest.
Frequently asked questions
What is the simple interest formula?
Interest = P × r × t, where P is the principal, r the annual rate and t the time in years.
How is simple interest different from compound interest?
Simple interest is only earned on the original principal. Compound interest is also earned on interest already added, so it grows faster.