CALCULATORS
Simple Interest Calculator
Estimate interest calculated on the original principal. Enter an annual rate and a term in years to see the interest and total.
Enter the principal, annual interest rate and term to calculate simple interest.
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How to calculate simple interest
Enter a positive principal, an annual interest rate from 0% to 100%, and a term greater than 0 and no more than 100 years. The term may include a fraction of a year. The calculator estimates the interest and total amount, using the same currency units as the principal.
Simple interest formula
Simple interest is calculated as I = P × r × t, where P is the principal, r is the annual interest rate expressed as a decimal, and t is the term in years. The total is the principal plus the interest; the calculation does not add interest to the principal during the term.
Estimate only
This estimate assumes a fixed annual rate and simple interest for the entire term. It does not include fees, taxes, compounding, payments, withdrawals or other terms. Actual products may use different methods; check the agreement or ask the provider.
For interest that compounds, use the Compound Interest Calculator, or estimate loan repayments with the Loan Calculator.