How EMI Is Calculated: Formula, Example and What Changes Your EMI

Understand the reducing-balance EMI formula, monthly rate conversion, tenure and total interest.

Equated Monthly Instalment (EMI) is the periodic payment used by many amortising loans. The payment contains both interest and principal, and the interest component generally changes as the outstanding balance changes.

A calculator is most useful when you understand what its inputs mean. This guide explains the standard formula and the assumptions behind it.

The EMI formula

For a fixed-rate monthly repayment schedule, the common formula is EMI = P × R × (1 + R)^N ÷ ((1 + R)^N − 1).

P is the principal, R is the monthly rate and N is the total number of monthly instalments. If the quoted annual rate is 10%, the simple monthly-rate input for this formula is 10 ÷ 12 ÷ 100.

Example

For ₹10 lakh at 10% for 5 years, the calculation uses 60 monthly instalments. The resulting EMI is a mathematical estimate of principal plus interest; processing fees and insurance are separate.

Why tenure matters

A longer tenure spreads repayment over more months. This can reduce the monthly payment while increasing the total interest paid.

Before using an EMI result

• Check whether the lender uses a fixed or floating rate.
• Check processing fees, insurance and other charges separately.
• Compare the lender's repayment schedule with the calculator.