What Is an Amortization Schedule?

An amortization schedule is the full month-by-month map of how a loan is repaid. It lists every instalment with three figures: the interest portion, the principal portion, and the outstanding balance that remains. Down the rows, the interest portion shrinks and the principal portion grows, until the final instalment clears the balance to exactly zero. On a ₹10,00,000 loan at 9% over 120 months — EMI ₹12,668 — the first month puts ₹7,500 toward interest and ₹5,168 toward principal, leaving ₹9,94,832 owing.

How each row is built

Every row of the schedule comes from two simple steps. First, the month’s interest is the outstanding balance multiplied by the monthly rate. At 9% per year, the monthly rate is 9 ÷ 12 ÷ 100 = 0.75%. Second, the principal repaid is the EMI minus that interest, and it reduces the balance carried into the next month. The EMI itself stays fixed (on a fixed-rate loan) and comes from the standard formula:

EMI = P × r × (1 + r)^n ÷ ((1 + r)^n − 1)

where P is the principal, r the monthly rate and n the number of months. See how EMI is calculated for the full derivation, and generate a complete schedule for any loan in the EMI calculator.

Worked example: the first months of a ₹10,00,000 loan

Here are the opening rows for ₹10,00,000 at 9% over 120 months, with an EMI of ₹12,668.

Trace the logic. In month 1, interest is ₹10,00,000 × 0.75% = ₹7,500; principal is ₹12,668 − ₹7,500 = ₹5,168; the balance drops to ₹9,94,832. In month 2, interest is charged on that lower balance, so it falls to ₹7,461 and principal rises to ₹5,206. By month 3 the interest is ₹7,422 and principal ₹5,245. The EMI never changes — only the split shifts, a little more toward principal each month.

The front-loaded pattern

This early stretch reveals the defining feature of a reducing-balance loan: interest is front-loaded. Because the balance is highest at the start, the earliest EMIs are mostly interest and only slowly chip away at principal. Over the full term the trend reverses — late instalments are almost entirely principal with a sliver of interest. This is the heart of reducing-balance EMI, and it explains why paying extra early has outsized impact.

Why the schedule matters in practice

An amortization schedule is more than an accounting table — it is a planning tool:

• It shows your real outstanding balance at any month, which you need for foreclosure, a balance transfer or selling a mortgaged asset.
• It reveals how much interest you’ve actually paid so far versus principal, which is rarely obvious from the EMI alone.
• It quantifies the benefit of prepayment. Because early rows are interest-heavy, a lump sum applied early erases more future interest — see how prepayment reduces EMI. Any prepayment rewrites the schedule from that point on.
• It helps you compare loans by showing total interest over the life of each option.

You can produce the full schedule for your own loan with the EMI calculator and read off the balance for any month.

The final instalment

At the other end of the schedule, the last EMI is designed to clear the loan precisely. By then the outstanding balance is tiny, so the interest component is minimal and almost the entire payment goes to principal — bringing the balance to zero. A well-formed schedule always ends at exactly zero; if it doesn’t, a small rounding adjustment is applied to the final instalment, which is normal and set by the lender.

Fixed vs floating and your schedule

On a fixed-rate loan, the schedule is stable: the EMI is constant and only the interest-principal split moves. On a floating-rate loan, a benchmark reset can change things — lenders typically either adjust the EMI or extend/shorten the tenure when the rate moves, which redraws the remaining schedule. Check your sanction terms to see how resets are handled, and treat the lender’s official schedule as the authoritative record.

Bottom line

An amortization schedule is the complete repayment map of a loan: every instalment’s interest, principal and falling balance, ending at zero. The split is the story — on a ₹10,00,000 loan at 9%, month 1 is ₹7,500 interest and ₹5,168 principal, but the interest shrinks and principal grows every month thereafter. Understanding it helps you time prepayments, plan a foreclosure and know your true outstanding balance. Generate your own with the EMI calculator, and remember these figures are estimates to confirm against your lender’s official schedule.