EMIplan

What is EMI? Complete Guide to How Loan EMI Works

Published: July, 2026  ·  7 min read  ·  EMIPlan Editorial Team

EMI stands for Equated Monthly Instalment - the fixed amount you pay every month to repay a loan, combining both principal and interest, until the loan is fully cleared. Whether it's a home loan, car loan or personal loan, almost every loan in India is repaid through EMIs.

This guide walks through exactly how EMI is calculated, why the same "9%" quoted rate can mean very different things depending on how it's structured, and why the composition of your EMI - how much goes to interest versus principal - changes every single month.

Worked Example
₹20,758
₹10,00,000 loan · 9% p.a. · 5-year tenure

The EMI Formula

Every bank and NBFC in India uses the same underlying formula, based on the reducing balance method - interest is charged only on the principal that's still outstanding, not on the original loan amount:

EMI = [P × R × (1+R)N] / [(1+R)N – 1]

P = Principal (the loan amount)
R = Monthly interest rate (annual rate ÷ 12 ÷ 100)
N = Tenure in months

For a ₹10,00,000 loan at 9% per annum over 5 years: P = ₹10,00,000, R = 9 ÷ 12 ÷ 100 = 0.0075, N = 60. Plugging these in gives an EMI of ₹20,758. Over 5 years, you'd pay a total of ₹12,45,501 - meaning ₹2,45,501 goes toward interest.

The Three Factors That Determine Your EMI

Only three numbers decide your EMI: the principal, the interest rate, and the tenure. Increase any one of them and your EMI moves - but not always in the direction people expect. Here's how tenure alone changes the EMI for the same ₹10 lakh loan at 9%:

Tenure Monthly EMI Total Interest Total Payment
3 Years ₹31,800 ₹1,44,790 ₹11,44,790
5 Years ✦ ₹20,758 ₹2,45,501 ₹12,45,501
7 Years ₹16,089 ₹3,51,483 ₹13,51,483
10 Years ₹12,668 ₹5,20,109 ₹15,20,109
15 Years ₹10,143 ₹8,25,680 ₹18,25,680
20 Years ₹8,997 ₹11,59,342 ₹21,59,342

Key insight: stretching the same ₹10 lakh loan from 5 to 20 years drops your EMI by more than half - but total interest rises from ₹2.45 lakh to ₹11.59 lakh. A lower EMI always comes at the cost of paying more, for longer.

Why Your EMI's Composition Changes Every Month

Even though the EMI amount itself stays fixed, what it's made of shifts dramatically over the loan's life. In the reducing balance method, interest is calculated on whatever principal is still outstanding - so early on, when the balance is high, most of your EMI goes toward interest. As the balance shrinks, more of each EMI goes toward principal.

On the same ₹10,00,000 loan at 9% for 5 years (EMI ₹20,758):

Month Interest Portion Principal Portion
Month 1 ₹7,500 ₹13,258
Month 60 (last) ₹155 ₹20,604

In month 1, over a third of your EMI (₹7,500 of ₹20,758) is pure interest. By the final month, interest is almost nothing and nearly the entire EMI reduces principal. This is exactly why prepaying early in a loan's life saves far more interest than prepaying the same amount later.

Flat Rate vs Reducing Balance - Why It Matters

Some lenders, especially for personal loans, gold loans or informal lending, quote a flat rate instead of reducing balance. In a flat-rate loan, interest is calculated on the full original principal for the entire tenure - even though you've already repaid part of it. This makes a flat rate sound deceptively low.

Reducing Balance (9% quoted)
₹20,758
Monthly EMI on ₹10 lakh over 5 years. Total interest: ₹2,45,501.
Flat Rate (same 9% quoted)
₹24,167
Monthly EMI on the same loan. Total interest: ₹4,50,000.

A flat rate of 9% behaves like a reducing-balance rate of roughly 16-17% - nearly double. This is why comparing loans purely on the quoted interest rate is risky. Always confirm whether the rate is flat or reducing balance, and ask the lender to state the effective annual rate (APR) for a true comparison.

Fixed vs Floating Interest Rate

🔒 Fixed Rate

Your interest rate - and therefore your EMI - stays the same for the entire tenure, regardless of what happens to market rates. Common for personal loans, car loans and some home loan products. Predictable, but you don't benefit if rates fall.

🔄 Floating Rate

Your rate moves with a benchmark (like the RBI repo rate or a bank's MCLR). Most Indian home loans are floating rate. Your EMI or tenure adjusts when the benchmark changes - you save when rates fall, but pay more if they rise.

EMI in Advance vs EMI in Arrears

There's one more variation worth knowing, especially for car and consumer loans: EMI in Arrears (the standard structure) means your first payment is due one full month after disbursement. EMI in Advance means the first EMI is collected on the day the loan is disbursed - effectively reducing your outstanding principal from day one, which results in a slightly lower total interest outgo over the loan's life. You can toggle between both on the EMIPlan calculator to see the difference for your own loan.

Calculate Your Own EMI in Seconds

Use EMIPlan's free calculator to work out the EMI, amortization schedule and prepayment savings for any home, car or personal loan.

Try the EMI Calculator →

Frequently Asked Questions

What does EMI stand for?

EMI stands for Equated Monthly Instalment - a fixed monthly payment that combines both principal repayment and interest, used to repay a loan over an agreed tenure.

Does the EMI amount ever change during the loan?

For a fixed-rate loan, no - the EMI stays constant for the entire tenure, only its interest-to-principal composition shifts each month. For a floating-rate loan, the EMI (or the remaining tenure) can change whenever the lender's benchmark rate changes.

Why is reducing balance cheaper than flat rate at the same quoted rate?

In a flat-rate loan, interest keeps being charged on the full original principal even after you've repaid part of it. In reducing balance, interest is charged only on what's actually still outstanding. At the same quoted 9%, this makes flat rate roughly equivalent to a 16-17% reducing-balance loan - nearly double the real cost.

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