How to read an amortisation schedule (and what it reveals)

Your lender gives you an EMI figure. The amortisation schedule tells you what that EMI is actually doing — and it is usually more surprising than people expect.

The columns

Each row is one instalment. A complete schedule has six things worth understanding:

Opening balance — what you owe at the start of the month. Interest is charged on this figure and nothing else.

EMI — your fixed instalment. It does not change (unless you prepay and choose to reduce it), but its composition changes every single month.

Interest — the opening balance multiplied by the monthly rate. Your annual rate divided by twelve. At 8.5%, that is 0.7083% a month.

Principal — whatever is left of the EMI after interest. This is the only part that actually reduces your debt.

Prepayment — any extra you paid that month, applied straight to the balance.

Closing balance — opening balance minus principal minus prepayment. It becomes next month's opening balance, which is why the whole thing compounds downward.

The first thing the table reveals

On a ₹50,00,000 loan at 8.5% over 20 years, the EMI is ₹43,391. In month one, roughly ₹35,417 of that is interest and only about ₹7,974 touches the principal.

Across the whole first year, 81% of what you pay is interest.

Principal does not overtake interest within a single instalment until month 143 — the twelfth year of a twenty-year loan. For more than half the term, you are mostly paying rent on money you already borrowed.

This is not a trick. It is the arithmetic of charging interest on an outstanding balance, and every lender in India works this way. But it explains two things at once: why your balance seems stuck in the early years, and why prepaying early is so disproportionately powerful.

Three things worth checking

1. Does the interest column match your rate?

Take any row. Divide the interest by the opening balance, multiply by 12, multiply by 100. You should get your annual rate. If you do not, something is off — a rate reset you were not told about, a fee bundled into the instalment, or an error. Ask.

2. What is the balance actually doing?

Compare the closing balance twelve rows apart. On our example loan, year one reduces the principal by only about ₹1 lakh out of ₹50 lakh. Knowing that in advance stops it from being demoralising, and tells you exactly how much a prepayment is worth.

3. Where does the crossover fall?

Find the first row where principal exceeds interest. That is the point the loan tips in your favour. The earlier it falls, the better the shape of your loan — and prepayments pull it forward dramatically.

Reading it by year instead

Month-by-month is 240 rows, which nobody reads. The year view is more useful: it shows how much principal and interest you paid in each calendar year, which is also what you need at tax time if you are claiming deductions.

Our calculator defaults to the yearly roll-up and expands any year to its months, so you can scan the shape and then drill into the detail. You can export the whole thing to CSV if you would rather work in a spreadsheet.

What a schedule cannot tell you

It assumes the rate you entered holds for the entire term. On a floating-rate loan it will not — when the benchmark moves, either your EMI or your tenure changes, and the schedule is redrawn. Treat it as an accurate picture of today's terms rather than a prediction.

It also excludes late-payment penalties, bundled insurance, and any charges outside the instalment itself.

The practical use

Print the schedule at the start of the loan and keep it. When you get a windfall — a bonus, a maturing deposit — look up the outstanding balance for that month, model the prepayment, and you will know within a minute whether it is worth using on the loan. That single habit is worth more than most borrowing advice.

General information about how loans work, not financial advice. Your lender's own statement is the authoritative record of your loan.