How EMI Is Calculated: Formula, Worked Example and 5 Ways to Reduce It
When a bank offers you a loan, the first number you see is the EMI, the fixed amount you pay every month. It is easy to compare loans by EMI alone, but the EMI hides the number that matters more: the total interest you will pay over the life of the loan. This guide shows how an EMI is calculated, how each payment is divided between interest and principal, and what really changes the cost of a loan.
The EMI formula
A standard reducing-balance loan with fixed monthly instalments uses this formula:
EMI = P × r × (1 + r)n ÷ ((1 + r)n − 1)
- P is the loan amount (the principal).
- r is the monthly interest rate, which is the annual rate divided by 12 and then by 100. A 10% annual rate gives r = 0.10 ÷ 12 = 0.008333.
- n is the number of monthly instalments. A 5-year loan has n = 60.
If the interest rate is 0%, the formula is not needed: the EMI is simply the loan amount divided by the number of months.
A worked example
Take a loan of ₹5,00,000 at 10% a year for 60 months. Putting the numbers into the formula gives an EMI of ₹10,623.52. Over 60 months you pay ₹6,37,411.34 in total, so the interest cost is ₹1,37,411.34, which is about 27% of the amount you borrowed.
You can check this yourself with the EMI Calculator, which uses the same formula and its starting values are exactly this example.
How each EMI splits into interest and principal
Interest each month is charged on the balance still owed. In the first month the balance is the full ₹5,00,000, so the interest portion is 5,00,000 × 0.10 ÷ 12 = ₹4,166.67. The rest of the EMI, about ₹6,457, reduces the principal.
The next month, interest is charged on a slightly smaller balance, so a little less of your EMI goes to interest and a little more goes to principal. Over time the split gradually tilts toward principal. This is why paying extra early in the loan saves more interest than paying the same extra amount near the end.
What a shorter or longer tenure does
Tenure is the lever people use most to fit a loan into their monthly budget, and it has a large effect on cost:
| Loan | Tenure | EMI | Total interest |
|---|---|---|---|
| ₹5,00,000 at 10% | 36 months | ₹16,133.59 | ₹80,809.37 |
| ₹5,00,000 at 10% | 60 months | ₹10,623.52 | ₹1,37,411.34 |
| ₹10,00,000 at 9% | 10 years | ₹12,667.58 | ₹5,20,109.29 |
| ₹10,00,000 at 9% | 15 years | ₹10,142.67 | ₹8,25,679.85 |
Extending the 10-year loan to 15 years lowers the EMI by about ₹2,525 a month, but adds roughly ₹3,05,570 in interest. A longer tenure can make a loan affordable, but it is the expensive way to do it.
Five ways to reduce the cost of a loan
- Compare total interest, not only EMI. Ask for the full repayment amount, or calculate it from the loan amount, rate and tenure.
- Choose the shortest tenure you can comfortably afford. Leave room in your budget for other expenses, because missed EMIs are costly.
- Make part-prepayments. For example, if you prepay ₹1,00,000 after 12 EMIs on the ₹5,00,000 loan and keep the same EMI, the loan ends in about 35 months instead of 48, and you save roughly ₹38,000 in interest. This assumes a fixed rate and no prepayment charges, so check your lender’s rules.
- Negotiate or compare the rate. Even a small difference in rate matters over a long tenure. Test it with the calculator by changing only the rate.
- Watch the extras. Processing fees, insurance and other charges are not part of the EMI formula but add to the real cost of borrowing.
What the formula does not include
The EMI formula assumes a fixed rate and equal monthly instalments from the day the loan starts. In real life, floating-rate loans can change the EMI or the tenure when the lender’s rate changes. The first instalment may be due after a different number of days, and fees and taxes are separate. Always rely on the repayment schedule from your lender for the final figures, and use a calculator for comparing options and planning.
Frequently asked questions
What is a good tenure for a loan?
There is no single answer. A shorter tenure costs less in interest, but the EMI must fit comfortably in your monthly budget. Compare two or three tenures with a calculator before deciding.
Is EMI the same as the interest rate?
No. The interest rate is the percentage charged on the balance. The EMI is the fixed monthly payment that repays both the interest and part of the principal.
Can I change my EMI later?
Many lenders allow prepayment or a change in tenure, sometimes with charges. Ask your lender for their rules.
Why does the bank’s EMI look slightly different from a calculator?
Differences can come from rounding, the number of days before the first instalment, processing fees, or a different calculation method for floating-rate loans.
Try the tools mentioned
Please note: This article is general information for learning and planning. Rates, rules and taxes can change, and examples use illustrative numbers. It is not tax, legal or investment advice, so please check official sources or speak to a qualified professional before you decide.
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