An EMI (Equated Monthly Instalment) is the fixed amount you pay a lender every month until a loan is cleared. Each EMI covers part interest and part principal, and while the total stays the same, that split shifts every month. This guide shows exactly how EMI is calculated, with a worked example you can reproduce, plus a free EMI calculator that does it instantly.
What an EMI is
When you borrow — a home loan, car loan or personal loan — the lender spreads repayment across a fixed number of months. Every month you pay the same EMI. Early on, most of it is interest on the outstanding balance; later, as the balance falls, more of each payment goes to principal. This is the reducing-balance method used by virtually all modern loans.
The EMI formula
EMI is calculated with this standard formula:
EMI = P × r × (1 + r)ⁿ ÷ ( (1 + r)ⁿ − 1 )
- P = principal (the amount borrowed)
- r = monthly interest rate = annual rate ÷ 12 ÷ 100
- n = loan tenure in months
The (1 + r)ⁿ terms are compounding at work — the same maths that grows a SIP, only here it's working out what fixed payment clears the balance in exactly n months.
Worked example
Suppose you borrow ₹10,00,000 for 20 years at 9% annual interest:
| Principal (P) | ₹10,00,000 |
| Monthly rate (r) | 9 ÷ 12 ÷ 100 = 0.0075 |
| Months (n) | 240 |
| Monthly EMI | ≈ ₹8,997 |
| Total paid over 20 years | ≈ ₹21,59,280 |
| Total interest | ≈ ₹11,59,280 |
You borrow ₹10 lakh but repay roughly ₹21.6 lakh — the extra ₹11.6 lakh is interest. Change any input in the EMI calculator and it recomputes the EMI, the total interest and the full month-by-month schedule instantly.
What changes your EMI
- Interest rate — even a 0.5% difference on a long loan changes the total interest by lakhs. Always compare rates.
- Tenure — a longer tenure lowers the monthly EMI but raises total interest, because you borrow for longer.
- Principal — a bigger down payment means a smaller loan and a smaller EMI.
How much of each EMI is interest?
In the example's first month, interest is ₹10,00,000 × 0.0075 = ₹7,500 — so of the ₹8,997 EMI, only about ₹1,497 reduces the principal. By the final year almost the whole EMI goes to principal. This is why paying extra early, when interest dominates, saves the most. The loan calculator shows the full amortisation split.
Tips to pay less interest
- Choose the shortest tenure you can afford — it cuts total interest sharply.
- Make part-prepayments early — they attack the principal while interest is highest.
- Compare rates before signing — a lower rate beats almost any other trick.
- Increase your down payment — borrowing less is the simplest saving of all.
FAQ
Is EMI calculated on reducing balance? Yes — standard loans charge interest only on the outstanding balance, which falls each month.
Does a longer tenure save money? It lowers the monthly EMI but increases total interest paid over the life of the loan.
Can I calculate EMI for any loan? Yes — the same formula works for home, car, personal and education loans.
Is my data private? Yes — every calculation runs in your browser and nothing is stored or uploaded.