How does EMI work? Formula, interest and loan repayment

What is an EMI?

EMI means equated monthly instalment. It is the fixed amount a borrower pays each month toward a loan such as a home loan, car loan or personal loan.

The monthly amount may stay the same for a period, but the split between interest and principal changes over time on a reducing-balance loan.

What is inside an EMI?

Each EMI has two parts: interest and principal. In a reducing-balance loan, interest is calculated on the outstanding loan amount. Early in the loan, the outstanding amount is high, so a larger share of the EMI goes to interest. As the balance falls, more of the same EMI goes toward principal.

Your loan statement or amortisation schedule shows this month-by-month split.

What affects your EMI?

Your EMI depends mainly on the loan amount, annual interest rate and repayment tenure. A larger loan or higher rate usually increases the EMI. A longer tenure can reduce the monthly EMI but can increase the total interest paid over the life of the loan.

Check that the EMI fits your monthly take-home pay before you choose a tenure: the salary calculator estimates in-hand pay from your gross salary or CTC.

Fixed rate vs floating rate

With a fixed-rate loan, the rate is set according to the lender’s terms for the agreed period. With a floating-rate loan, the rate can change when the linked benchmark or lender’s applicable rate changes.

A rate change can affect the EMI, the remaining tenure, or both depending on the loan terms. Check the lender’s notice rather than assuming the monthly amount will never change.

Does prepayment help?

Paying extra principal can reduce the outstanding balance and may reduce future interest, but the effect depends on timing and the loan terms. Check whether any prepayment conditions or charges apply before paying a lump sum.

To see how a one-time or regular prepayment could change the interest and the loan tenure for your own balance, rate and remaining term, try the home loan prepayment calculator. It assumes a fixed rate and an unchanged EMI, so treat the result as an estimate.

What should you check before signing?

Check the interest type, processing fee, insurance, prepayment charge, late-payment penalty, total repayment amount and amortisation schedule. Read the lender’s key facts statement and compare the total cost, not only the headline EMI.

If two loans have similar EMIs but different tenures or fees, the cheaper-looking monthly payment may still cost more overall.