How EMI Is Calculated: A Complete Guide
Understand the math behind your loan EMI, why interest is front-loaded, and how prepayment changes the picture.
Every loan — home, personal, car or education — is repaid through Equated Monthly Installments, or EMIs. Understanding how an EMI is calculated helps you compare loan offers intelligently and make informed decisions about tenure and prepayment.
The EMI formula
Lenders use the reducing-balance method, expressed as:
EMI = P × r × (1+r)n / ((1+r)n − 1)
Where P is the principal borrowed, r is the monthly interest rate (annual rate divided by 12 and by 100), and n is the total number of monthly installments.
Why interest is front-loaded
Because interest is charged on the outstanding balance, the interest component of your EMI is highest in the first year and gradually decreases, while the principal component increases. This is why prepaying early in a loan's life saves far more interest than prepaying the same amount later.
How tenure affects your EMI
A longer tenure spreads the same principal over more installments, lowering the monthly EMI — but it increases the total interest paid because you carry a balance for longer. A shorter tenure raises the EMI but reduces total interest substantially. There's no universally "right" tenure; it depends on your monthly cash flow and how much total interest you're willing to pay.
Reading an amortization schedule
An amortization schedule breaks down every EMI into its principal and interest components, month by month, along with the remaining loan balance. Reviewing it helps you see exactly how much interest you'd save by prepaying at a given point in the loan.