Simple Interest Calculator
Enter principal, annual rate, and time. Get interest and total repayment.
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Open BusinessOSCommon questions
When is simple interest used?
Short-term loans, some auto loans, and treasury bills. Rare for savings accounts, which almost always compound.
How do I convert an annual rate to monthly?
For simple interest, monthly rate = annual rate ÷ 12. For compound, it's different.
Is simple interest better for the borrower?
Yes — pays less than compound interest for the same principal and rate.