Before you sign for a home, car or personal loan, one number decides whether it fits your budget: the EMI, or Equated Monthly Instalment. Knowing how it’s calculated — not just what a bank quotes — helps you compare offers, judge how tenure affects total interest, and avoid borrowing more than you can comfortably repay. Here’s the real formula, a worked example, and the factors that move it.
Quick answer: EMI = P × r × (1+r)ⁿ ÷ [(1+r)ⁿ − 1], where P is the loan amount, r is the monthly interest rate, and n is the number of monthly instalments. Rather than compute the powers by hand, enter your figures into the free AMTake EMI Calculator for the exact instalment, total interest and a full breakdown.
1What an EMI actually is
An EMI is a fixed amount you pay every month until the loan is cleared. It stays the same each month, but its make-up changes: early instalments are mostly interest with a little principal, and over time that flips until the final payments are almost all principal. This is called amortisation. The EMI is engineered so that this changing split still adds up to the same total every month across the whole tenure.
2The EMI formula, explained
EMI = P × r × (1 + r)ⁿ ÷ [ (1 + r)ⁿ − 1 ]
- P — Principal: the amount you actually borrow (loan sanctioned, not the asset price).
- r — Monthly rate: the annual interest rate ÷ 12 ÷ 100. A 10% annual rate is 0.10 ÷ 12 = 0.008333 per month.
- n — Number of months: the tenure in months. Five years is 5 × 12 = 60.
The (1 + r)ⁿ term is compounding at work — it’s why a longer tenure lowers the monthly payment but raises the total interest, as you’ll see next.
3A worked example
Take a ₹5,00,000 loan at 10% per year for 5 years. So P = 5,00,000, r = 0.008333, n = 60. Plugging in:
| Figure | Value |
|---|---|
| Monthly EMI | ≈ ₹10,624 |
| Total paid over 60 months | ≈ ₹6,37,440 |
| Total interest | ≈ ₹1,37,440 |
You borrow ₹5 lakh and repay about ₹6.37 lakh — the extra ₹1.37 lakh is the cost of the loan. Notice that interest is over a quarter of the principal even at a moderate rate, which is why the rate and tenure you choose matter so much.
4How tenure changes the picture
Stretching the tenure lowers the monthly EMI but increases the total interest, because you’re borrowing the money for longer. Same ₹5,00,000 at 10%:
| Tenure | Approx. EMI | Approx. total interest |
|---|---|---|
| 3 years | ₹16,134 | ₹80,824 |
| 5 years | ₹10,624 | ₹1,37,440 |
| 7 years | ₹8,301 | ₹1,97,284 |
A longer tenure is not a cheaper loan. The 7-year option saves about ₹7,800 a month versus 3 years, but costs roughly ₹1.16 lakh more in total interest. Pick the shortest tenure whose EMI you can comfortably afford.
5What raises or lowers your EMI
- Interest rate. Even a 0.5% difference adds up over years — always compare the rate, not just the EMI a lender advertises.
- Loan amount. A bigger down payment means a smaller principal and a smaller EMI. Borrow only what you need.
- Tenure. Longer lowers the monthly outgo but raises total interest, as shown above.
- Prepayment. Paying extra toward the principal shortens the loan and cuts interest sharply, especially in the early, interest-heavy years.
6Calculate yours in seconds
The EMI Calculator does the full formula for you and shows the monthly instalment, total interest and principal-versus-interest split — adjust the rate or tenure and watch the numbers update. To compare a recurring investment against loan repayment, see the SIP Calculator, and for a broader loan view with amortisation, the Loan Calculator. Everything runs in your browser, so your figures stay private.
EMI results are estimates for planning based on a reducing-balance method. Your lender’s final figure may differ slightly due to processing fees, rounding or the exact day-count convention — always confirm with the lender before committing.
7Frequently Asked Questions
What is the formula to calculate EMI?
EMI = P × r × (1+r)ⁿ ÷ [(1+r)ⁿ − 1], where P is the principal, r is the monthly interest rate (annual rate ÷ 12 ÷ 100) and n is the number of monthly instalments.
How do I calculate the EMI on a ₹5 lakh loan at 10% for 5 years?
With P = 5,00,000, r = 0.008333 and n = 60, the EMI works out to about ₹10,624 a month, with roughly ₹1,37,440 paid as total interest.
Does a longer tenure reduce my loan cost?
No. A longer tenure lowers the monthly EMI but increases the total interest you pay, because the principal is outstanding for more months.
Is EMI calculated on a reducing balance?
Standard bank EMIs use the reducing-balance method — interest each month is charged only on the remaining principal, so the interest portion falls as the loan progresses.
Will prepaying my loan lower my EMI?
Prepayment usually keeps the EMI the same but shortens the tenure and cuts total interest. Some lenders instead let you reduce the EMI — ask which option applies.
Know the EMI, the total interest, and the tenure trade-off before you sign.
