Rate of Interest Calculator
Calculate the effective rate of interest from investment amounts
Details
Enter amounts and click Calculate Rate
Annual Rate of Return
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This is the effective annual rate of interest / return on your investment.
How to Use
- Enter the Principal Amount (amount invested or lent).
- Enter the Maturity / Total Amount received at the end.
- Enter the Time Period in years.
- Click Calculate — the effective annual rate of return is displayed.
When Do You Need This Calculator?
Use this when you know what you invested and what you received, but want to find the effective annual rate of return (CAGR). Common use cases include comparing chit funds, evaluating post office schemes, or verifying an agent's claim.
CAGR Formula
Where n = number of years. The result multiplied by 100 gives the percentage rate per annum.
Flat Rate vs Reducing Balance Rate
A loan advertised at "flat 10%" is actually ~18–20% on reducing balance. Always convert flat rates to reducing-balance equivalents before comparing loan offers. This calculator helps you verify the true rate from any investment or loan.