How Loan EMI Is Calculated: A Worked Example Anyone Can Follow
An EMI, or equated monthly instalment, is the fixed amount you pay each month until a loan is cleared. Banks quote it in seconds, but understanding where the number comes from helps you compare offers sensibly.
The formula
EMI = P × r × (1 + r)^n ÷ ((1 + r)^n − 1)
- P is the principal, the amount borrowed.
- r is the monthly interest rate: the annual rate divided by 12 and by 100.
- n is the number of monthly payments.
A worked example
Suppose you borrow 500,000 at 10 percent a year for 5 years (60 months).
- Monthly rate: r = 10 ÷ 12 ÷ 100 = 0.008333.
- Growth factor: (1 + r)^60 ≈ 1.6453.
- EMI = 500,000 × 0.008333 × 1.6453 ÷ (1.6453 − 1) ≈ 10,624 per month.
- Total paid: 10,624 × 60 ≈ 637,411, so the total interest is about 137,411.
How each payment is split
Early payments are mostly interest. In month one the interest is 500,000 × 0.008333 ≈ 4,167, so about 6,457 of your 10,624 reduces the principal. Each month the balance falls, interest shrinks, and more of the fixed payment goes to principal. This pattern is called amortisation.
What changes the EMI
- Longer tenure lowers the monthly payment but increases the total interest. Stretching the same loan to 10 years drops the EMI to about 6,608, but total interest rises to roughly 292,900.
- Higher rate raises both. At 12 percent over 5 years, the EMI is about 11,122 and interest about 167,300.
- Larger principal scales the EMI proportionally.
Beyond the headline rate
Compare offers using the total cost, not only the EMI. Look at:
- Processing or origination fees
- Insurance requirements
- Prepayment or foreclosure charges
- Whether the rate is fixed or floating (a floating rate can change your EMI or tenure)
- Reducing-balance versus flat-rate calculation. Flat-rate quotes look lower but cost more in practice because interest is charged on the original amount throughout.
Prepaying wisely
Paying extra toward principal early in the loan saves the most interest. Confirm whether your lender applies the extra payment to principal and whether any penalty applies.
A sensible affordability check
Many lenders and advisers suggest keeping total monthly debt payments to a modest share of income, often cited around a third or less. Your own circumstances, savings and emergency buffer matter more than any rule.
Disclaimer
This article is educational and not financial advice. Final figures depend on your lender's terms, rounding rules and fees, so check with the lender before deciding.
Calculate several scenarios, compare the total cost, and choose the loan you can repay comfortably.
