How EMI works: what tenure and prepayment really cost you
An EMI is the fixed monthly amount that repays a loan with interest. Lenders usually lead with this number because it is the one that feels affordable. It doesn't tell you what the loan costs. For that, you need to look at the total paid over the full tenure. The examples below are calculated with the same formula as our EMI calculator. They are illustrations, not quotes from any lender.
The formula
EMI = P × r ÷ (1 − (1 + r)−n), where P is the loan amount, r is the monthly interest rate (the annual percentage ÷ 1,200) and n is the number of months. You don't need to work it by hand, but it shows that only three things matter: how much you borrow, at what rate and for how long.
Why the early payments feel so slow
Most Indian retail loans use a reducing balance, which means interest is charged each month on what you still owe. Take ₹5,00,000 at 10% for 5 years. The EMI is ₹10,624. In the first month, interest on the full balance is ₹4,167, so only ₹6,457 of your payment reduces the loan. As the balance falls, the interest part shrinks and the principal part grows. The longer the tenure, the more pronounced this effect is. It is why a home-loan balance can seem barely to move for years.
What tenure does to the cost
Here is a ₹30,00,000 loan at 8.5% over three tenures:
| Tenure | EMI | Total interest | Total paid |
|---|---|---|---|
| 15 years | ₹29,542 | ₹23,17,594 | ₹53,17,594 |
| 20 years | ₹26,035 | ₹32,48,327 | ₹62,48,327 |
| 30 years | ₹23,067 | ₹53,04,266 | ₹83,04,266 |
Going longer does lower the EMI, but the total interest climbs much faster than the EMI falls. Before you choose the longest tenure on offer, try the question the other way around: what is the shortest tenure whose EMI you could still pay in a bad month?
What one prepayment does
Because interest is charged on the balance, money paid early saves interest for every remaining month. Take the same loan over 20 years: the EMI is ₹26,035 and total interest is ₹32,48,327. Pay one extra ₹1,00,000 at the end of the first year and keep the EMI the same. The loan now finishes in about 222 months rather than 240, and total interest falls to about ₹28,77,941, a saving of ₹3,70,386. That assumes the rate never changes, which floating-rate loans don't promise. Treat it as a sense of scale.
What the EMI doesn't show
- Processing fees and GST on them. These are often paid upfront or deducted from the amount you receive, so you get less than you borrowed but pay interest on the full sum.
- Bundled insurance. Sometimes it is added to the loan, so you pay interest on the premium too. Ask whether it is optional.
- Floating rates. When the benchmark changes, your EMI or tenure can change. Many lenders extend the tenure rather than raise the EMI, so check your statement after a rate rise.
- Prepayment charges. Ask about these before you sign. For floating-rate home loans taken by individuals, RBI rules generally don't allow foreclosure charges; other loans can differ.
- "No cost" offers. The interest may be offered back as a discount, but fees, GST or a lost cash discount can remain. Compare what you would pay in total against paying the full amount today.
A simple way to compare two offers
- Get the amount, rate, type of rate, tenure and all fees from each lender in writing.
- Run both offers in the calculator at the same tenure, and note the total interest.
- Add the fees to each total.
- Compare the totals, then consider the things numbers don't capture, such as prepayment terms and service.
This guide explains the arithmetic and isn't financial advice. Your lender's sanction letter and repayment schedule are what count. Rates and rules change, so check them with your lender or on the RBI website.