Simple Interest Calculator
Calculate simple interest earned or owed on a principal amount over time, plus the total amount at the end of the term.
Inputs
Result
Fill in the fields to see your result.
Formula
Simple interest grows linearly: it is calculated only on the original principal, not on any interest already earned.
SI = P × R × T ÷ 100Step-by-step
- 1
Enter the principal
Type in the initial amount of money invested or borrowed.
- 2
Enter the annual interest rate
Type in the yearly interest rate as a percentage.
- 3
Enter the time period
Type in the length of time in years the money is invested or borrowed for.
- 4
Read the results
See the total interest earned and the final amount, principal plus interest.
Examples
$1,000 at 5% for 3 years
- principal
- 1000
- rate
- 5
- time
- 3
Interest earned $150.00, total amount $1,150.00
$5,000 at 3.5% for 6 months
- principal
- 5000
- rate
- 3.5
- time
- 0.5
Interest earned $87.50, total amount $5,087.50