Interest rate calculator
Work back from values or EMIs to an annual rate.
Effective annual investment return
For illustration only. Read the assumptions below for the full picture.
Understand your result.
Work backwards to an investment’s effective annual growth rate or a loan’s implied nominal annual rate. Select the mode that matches your cash flows.
Investment growth has no interim flows. Loan mode infers a rate from principal, term and fixed EMI, excluding upfront fees.
A worked example.
Using this calculator’s default inputs, effective annual investment return is 8.45%. This is an illustration of the stated formula, not a forecast.
See the example inputs
| Calculate the rate for | Investment growth |
|---|---|
| Starting value / loan principal | ₹5,00,000 |
| Final investment value | ₹7,50,000 |
| Period / repayment term | 60 months |
A common mistake to avoid
Calling the inferred loan rate a fee-inclusive APR.
Questions you might have.
Can the investment result be negative?
Yes. A lower final value implies a negative growth rate.
Why can an EMI be impossible to fit?
An EMI below principal divided by months cannot repay a non-negative-interest loan within that term.
Prepared by INDwise · Calculation checks: 29 October 2026 · How we check the maths · Report a correction
How we calculate it
Investment: effective annual return = (final/principal)^(12/months) − 1. Loan: solve the monthly reducing-balance EMI equation numerically for the nominal annual rate.
Assumptions & things to know
Growth mode has no interim cash flows. Loan mode assumes fixed equal EMIs, no fees or balloon payment; inferred nominal rate is not a fee-inclusive APR. The unused final-value or EMI input is ignored.
Your privacy & sharing
Your financial inputs are used only within this page. Saved calculators use this browser’s local storage. Sharing creates a link with the entered values, so anyone with that link can see those values. A downloaded summary stays on your device.