How Loan EMI Really Works: Interest, Tenure and Cost
When you take a loan, the number you see first is the monthly EMI. It's the figure that has to fit your budget, so it's tempting to choose the loan with the lowest one. But the EMI tells you very little about what the loan will actually cost. This guide explains what's inside an EMI, using a single example you can check yourself in the EMI Calculator.
What an EMI is made of
An EMI is a fixed monthly payment made up of two parts: interest on the balance you currently owe, and principal, which reduces that balance. The total never changes, but the split does. Each month the interest is calculated on what's left, so as the balance falls, the interest part shrinks and the principal part grows. The standard formula is EMI = P × r × (1 + r)n ÷ ((1 + r)n − 1), where P is the loan, r the monthly interest rate (the annual rate ÷ 12) and n the number of months.
One example: ₹10,00,000 at 9% for 20 years
The EMI is ₹8,997. Here is where that money goes at different points in the loan:
| Month | Interest part | Principal part | Balance still owed |
|---|---|---|---|
| 1 | ₹7,500 | ₹1,497 | ₹9,98,503 |
| 12 | ₹7,372 | ₹1,626 | ₹9,81,273 |
| 60 (year 5) | ₹6,670 | ₹2,327 | ₹8,87,070 |
| 120 (year 10) | ₹5,354 | ₹3,643 | ₹7,10,259 |
| 180 (year 15) | ₹3,293 | ₹5,704 | ₹4,33,428 |
| 240 (year 20) | ₹67 | ₹8,930 | ₹0 |
Three things stand out:
- The first year is about 83% interest. Of the roughly ₹1,08,000 you pay in year one, about ₹89,000 is interest.
- After five years you still owe ₹8,87,070 of the original ₹10,00,000. You've paid more than ₹5,00,000 in instalments but cleared only about ₹1,13,000 of the loan.
- Principal only overtakes interest around month 149, in the thirteenth year.
That is why a loan feels like it barely shrinks at first. It's also why paying a loan down early saves so much: money paid towards principal in the early years prevents years of interest from ever being charged on it.
Tenure: lower EMI, higher cost
| Tenure | EMI | Total interest | Total paid |
|---|---|---|---|
| 5 years | ₹20,758 | ₹2,45,501 | ₹12,45,501 |
| 10 years | ₹12,668 | ₹5,20,109 | ₹15,20,109 |
| 20 years | ₹8,997 | ₹11,59,342 | ₹21,59,342 |
Going from 5 to 20 years more than halves the EMI, but multiplies the interest by almost five. A longer tenure doesn't make a loan cheaper; it spreads the same debt over more months of interest.
The interest rate
Small differences in rate add up over a long loan. For ₹10,00,000 over 20 years:
| Rate | EMI | Total interest |
|---|---|---|
| 8% | ₹8,364 | ₹10,07,456 |
| 9% | ₹8,997 | ₹11,59,342 |
| 10% | ₹9,650 | ₹13,16,052 |
One percentage point changes the total interest by well over ₹1,50,000 here, which is why it's worth comparing offers and asking whether your rate can be negotiated.
How to compare loans sensibly
- Compare total interest, not the EMI. A low EMI can hide a long, expensive loan.
- Pick the shortest tenure you can comfortably afford. Leave room in your budget for surprises.
- Add the fees. Processing fees, insurance and other charges raise the real cost, and the calculator doesn't include them.
- Know whether your rate is fixed or floating. A floating rate can change your EMI or your tenure over time.
- Ask about part-prepayment. Paying extra towards principal usually reduces total interest. Check your lender's rules, because some charge fees for it.
The limits of any EMI calculator
These figures assume a fixed rate for the full tenure and a standard reducing-balance loan. Your lender's own schedule may differ slightly because of rounding, the date of the first instalment and extra charges, so use a calculator to understand and compare, and rely on your lender's loan schedule for the exact amounts.
Try your own loan amount, rate and tenure.
Open the EMI Calculator →Keep reading
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