%FINANCE
Interest Rate Calculator
Solve for the simple annual interest rate when principal, interest and time are known.
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Formula
Rate = interest ÷ (principal × time) × 100.
Rate = interest ÷ (principal × time) × 100.
How it works
1
Enter the principal.
2
Enter the total simple interest and time.
3
Review the implied annual rate.
Important notes
This formula assumes simple interest rather than compounding.