Simple Interest Calculator
Calculate simple interest on a principal over time — no compounding.
Interest
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Total amount
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Results update as you type.
About this calculator
Simple interest is charged only on the original principal, not on accumulated interest. It is common for short-term and some car or personal loans. Enter the principal, annual rate and time to see the interest and the total.
Frequently asked questions
What is the simple interest formula?
Interest = Principal x Rate x Time, with the rate as a decimal. 5,000 at 5% for 3 years earns 5000 x 0.05 x 3 = 750.
How is simple interest different from compound interest?
Simple interest is calculated only on the principal, so it grows in a straight line. Compound interest is calculated on the principal plus prior interest, so it grows faster over time.
Results are estimates for general guidance only, not financial, medical or tax advice.