Simple Interest Calculator
Work out simple interest on a loan or deposit. Enter the principal, the annual interest rate and the time in years, and the calculator shows the interest earned or owed and the final total.
$
%
Total interest
$750.00
Final amount$5,750.00
Principal$5,000.00
How it works
Simple interest is calculated only on the original principal:
Interest = Principal × Rate × Time ÷ 100
The final amount is the principal plus the interest. Unlike compound interest, simple interest does not earn interest on previously added interest.
Frequently asked questions
How is simple interest different from compound interest?
Simple interest is charged only on the original principal. Compound interest is charged on the principal plus any interest already added, so it grows faster.
What time unit should I use?
Enter the time in years. You can use decimals for partial years, for example 1.5 for eighteen months.
Can I use it for savings and loans?
Yes. The same formula gives the interest earned on a deposit or the interest owed on a simple-interest loan.