EMI Calculator

The EMI Formula, and What Each Part Does

An equated monthly instalment is a single fixed payment that clears both interest and principal over a fixed term. It is derived from the present value of an annuity, and written out it is EMI = P × r × (1+r)^n / ((1+r)^n − 1), where P is the amount borrowed, n is the number of monthly instalments and r is the monthly interest rate.

The detail that trips people up is r. Lenders quote an annual rate, but the formula needs a monthly one, so a quoted 8.5% becomes 0.085 ÷ 12, or roughly 0.00708 per month. Similarly n is months, not years: a twenty-year loan is 240, not 20. Getting either of these wrong produces an answer that is wrong by an order of magnitude, which is usually obvious, or subtly wrong in a way that is not.

A worked example

Borrow ₹30,00,000 at 8.5% for 20 years. The monthly rate is about 0.708% and there are 240 instalments, which gives an EMI of approximately ₹26,035. Over the full term you pay about ₹62.5 lakh, of which roughly ₹32.5 lakh is interest. In other words the interest slightly exceeds the amount borrowed, which surprises most first-time borrowers and is entirely normal at that rate and tenure.

Why Your Early EMIs Barely Touch the Principal

The instalment stays constant but its composition changes every month. Interest is charged on the outstanding balance, so when the balance is at its largest, at the start, interest consumes most of the payment. As the balance falls the interest portion shrinks and the principal portion grows, slowly at first and then quickly near the end.

In the example above, the first instalment is roughly ₹21,250 interest and only ₹4,785 principal. It takes over a decade before the split crosses the halfway point. This is the single most useful thing to understand about a long loan, because it explains why the outstanding balance after five years of diligent payment feels disappointingly close to where it started, and why prepayments made early are so much more effective than the same amount paid later.

What Tenure Actually Costs You

Stretching a loan reduces the monthly instalment and increases the total paid, but not proportionally. The table shows the same ₹30 lakh at 8.5%.

Read the last two rows together. Extending from 25 to 30 years lowers the instalment by about ₹1,090 a month but adds roughly ₹10.5 lakh of interest. The relationship flattens out: each extra block of years buys progressively less relief on the monthly figure while adding steadily more to the total. Seeing both columns at once is the point of an EMI calculator.

Prepayment: Cut the EMI or Cut the Tenure

When you make a lump-sum prepayment most lenders will let you choose between two outcomes. Reducing the instalment keeps the original end date and frees up monthly cash flow. Reducing the tenure keeps the instalment where it is and finishes the loan earlier. The second saves substantially more interest, because interest accrues on time as well as on balance, but it does nothing for your monthly budget.

There is no universally correct choice; it depends on whether the constraint you are managing is cash flow or total cost. What is worth knowing is that lenders often default to reducing the EMI unless you ask otherwise, and that the request usually has to be made in writing at the time of prepayment. Floating rate home loans to individuals generally cannot carry prepayment penalties in India, while fixed rate loans and many personal loans can, so check the sanction letter before planning around it.

Why Your Actual Outgo Exceeds the EMI

The instalment is not the whole cost of a loan. Before disbursement there is typically a processing fee, legal and technical valuation charges, stamp duty on the loan agreement in some states, and often a bundled insurance premium that may be financed into the loan itself. During the loan there can be conversion fees when you renegotiate a rate, and charges for statements or foreclosure letters.

Some of these are unavoidable and some are negotiable, but they belong in any comparison between lenders. A slightly lower headline rate paired with a much larger processing fee can be the worse deal on a short tenure and the better one on a long tenure, which is a calculation worth doing explicitly rather than by instinct.

Floating Rates and What This Calculator Assumes

This calculator models a fixed rate for the full tenure. Most Indian home loans are floating, benchmarked to an external rate that resets periodically. When the benchmark moves, lenders typically hold the instalment steady and adjust the tenure instead, which means a rate rise can silently extend your loan by years without changing anything you see in your bank statement.

It is worth asking your lender for the revised amortisation schedule after any reset, because the tenure change is the part that is easy to miss. Re-running this calculator with the new rate and your current outstanding balance will show you what the remaining term should look like.

Your Loan Details Never Leave This Page

Loan amounts, interest rates and tenures say a great deal about your finances, and there is no reason for any of it to be transmitted to run a formula. Everything on this page is computed in your browser using JavaScript that loaded with the page. Nothing you enter is uploaded, saved between visits, or attached to an analytics event, and the downloadable amortisation schedule is assembled on your own device rather than fetched from a server. You can confirm all of this by opening your browser's network tab, or simply by disconnecting from the internet and watching the calculator continue to work.

Frequently Asked Questions