Estimate interest earned only on your original starting amount.
The result
Enter your numbers, then calculate.
Formula, example & assumptions
Behind the answer
How it works
Simple interest does not add earned interest back to the principal. Multiply the original amount by the annual rate as a decimal and by the duration in years.
Interest = principal × annual rate ÷ 100 × years
A worked example
1,000 at 5% a year for 3 years earns 150 in simple interest. The principal plus interest is 1,150.