What Is an EMI?
EMI stands for Equated Monthly Instalment — a fixed amount you pay every month toward a loan until it’s fully repaid. Each EMI includes two parts: a portion that reduces your outstanding loan (principal) and a portion that pays interest on the amount still owed.
The EMI Formula
EMI is calculated using:
EMI = [P × r × (1+r)n] / [(1+r)n − 1]
Where P is the loan principal, r is the monthly interest rate (annual rate divided by 12, expressed as a decimal), and n is the total number of monthly instalments (loan tenure in months).
Why the Principal/Interest Split Changes Every Month
In the early months of a loan, most of your EMI goes toward interest because the outstanding principal is still high. As you keep paying, the outstanding principal shrinks, so less interest accrues each month — meaning a larger share of each later EMI goes toward the principal. This is why paying off a loan early saves more interest than it might initially seem: you’re cutting off interest at the point where it’s the largest part of your payment.
What Changes Your EMI Amount
Three things determine your EMI: the loan amount, the interest rate, and the tenure. A longer tenure lowers your monthly EMI but increases the total interest you pay over the life of the loan, since interest keeps accruing for longer. A shorter tenure raises your EMI but reduces total interest paid. There is no single “right” tenure — it depends on how much monthly payment you can comfortably afford versus how much total interest you’re willing to pay.
Prepayment and Its Effect
Making a lump-sum prepayment reduces your outstanding principal directly, which reduces the interest charged in every subsequent month. Many lenders allow prepayment with little or no penalty on floating-rate loans — checking your specific loan’s prepayment terms is worthwhile if you expect to have surplus funds later.