How Home Loan EMI Works in India

The math behind your EMI, why early EMIs are mostly interest, and how prepayment saves lakhs over 20 years.

1.What is an EMI?

EMI stands for Equated Monthly Instalment — the fixed amount you pay your bank every month until your loan is repaid. Every EMI has two components: interest (what you pay the bank for lending you money) and principal (repayment of the original loan amount). The split between these two changes dramatically over the loan tenure.

2.The reducing balance formula

Indian banks use reducing balance interest: you only pay interest on the outstanding principal. The formula is EMI = P × r × (1+r)^n / ((1+r)^n − 1), where P is principal, r is monthly interest rate (annual ÷ 12 ÷ 100), and n is tenure in months. This is identical across all major Indian lenders — the only variable is the rate.

3.Why early EMIs are mostly interest

In year 1 of a 20-year ₹50 lakh home loan at 8.5%, your ₹43,391 EMI splits as ₹35,417 interest + ₹7,974 principal. In year 20, the same ₹43,391 EMI is ₹305 interest + ₹43,086 principal. This is because interest compounds on the outstanding principal. The implication: prepayments in the first 5-7 years save disproportionately more interest than prepayments in the last 5 years.

4.The prepayment math

On a ₹50 lakh loan at 8.5% for 20 years, prepaying ₹1 lakh in year 2 saves ₹3.2 lakh in total interest and shortens the tenure by 8 months. The same ₹1 lakh prepaid in year 15 saves only ₹28,000 and shortens tenure by 2 months. Early prepayments are 10x more valuable. If you get a bonus, put it toward the loan in year 1-5.

5.Floating vs fixed rate

95% of Indian home loans are floating rate — the interest moves with the RBI repo rate. Fixed rate loans are usually 0.5-1% higher. For a 20-year horizon, floating almost always wins because rates trend down over long periods in India, and the RBI Monetary Policy Committee uses rate cuts as a growth lever during slowdowns.