Quick answer
EMI (Equated Monthly Installment) is calculated as EMI = P × r × (1+r)ⁿ / ((1+r)ⁿ − 1), where P is the loan principal, r is the monthly interest rate, and n is the number of monthly installments. A fixed-rate loan keeps that EMI constant for the full tenure; a floating-rate loan recalculates it whenever the reference rate changes.
Every fixed-rate installment loan — a home loan, a car loan, a personal loan — amortizes the same way: one constant monthly payment, but a changing split between interest and principal underneath it. Understanding that split is what actually helps you decide whether to make extra payments, and when.
Why early payments are mostly interest
In the first year of a 20-year home loan, most of each EMI goes toward interest — the lender is paid first on the money it's still owed, calculated on the full outstanding balance. As that balance shrinks year over year, a growing share of the same fixed payment starts paying down principal instead. That's why an extra payment made early in a loan's life saves far more total interest than the identical extra payment made in year 15.
Fixed-rate vs floating-rate: what actually changes
Fixed-rate vs floating-rate home loans
| Fixed-rate | Floating-rate | |
|---|---|---|
| Monthly EMI | Constant for the full tenure | Recalculates when the reference rate changes |
| Rate risk | None — rate is locked | You bear the risk if rates rise |
| Typical starting rate | Often slightly higher | Often slightly lower |
| Best suited for | Budget certainty, rising-rate environments | Falling-rate environments, shorter tenures |
Formula used:
EMI = P × r × (1 + r)ⁿ / ((1 + r)ⁿ − 1) — r = annual rate ÷ 12, n = tenure in months
What the amortization schedule actually shows
A year-by-year amortization schedule breaks each year's total payments into the interest portion and the principal portion, plus the running outstanding balance. It's the clearest way to see exactly how much of the loan's total cost is interest versus principal, and how that ratio flips over the tenure. Run your own numbers — loan amount, rate, and tenure — in the Loan EMI & Salary Tax Calculator, which generates this full schedule instantly.
What this doesn't account for
- A lender's processing fee, charged once upfront, outside the EMI math itself
- Mandatory loan insurance premiums, which some lenders bundle into the EMI and some don't
- A floating rate's actual future path — only you (or your lender) can know when and how much it will move
Before applying, check whether the EMI fits comfortably inside your take-home income — the Savings & Inflation Calculator is a useful companion for seeing how a large fixed monthly outflow interacts with your broader savings plan over the same years.
For educational and informational purposes only — not financial, investment, trading, legal or tax advice. See our full Financial Disclaimer.