Home Loan EMI: How It's Calculated & What Banks Don't Tell You
Your bank's EMI calculator shows a clean monthly number. But hidden inside that figure is a schedule that frontloads nearly 80% of your 20-year interest burden into the first 10 years. Here's what the full picture looks like — and the decisions that can save you ₹15–25 lakh over your loan tenure.
The Reducing Balance Method — How EMI Is Actually Computed
Every home loan in India uses the reducing balance (diminishing balance) method. Interest is charged on the outstanding principal — not the original loan amount. The EMI formula is:
EMI = [P × R × (1+R)^N] / [(1+R)^N – 1]
Where P = Principal, R = Monthly interest rate (annual rate ÷ 12), N = Tenure in months.
Example: ₹50 lakh loan at 8.5% for 20 years (240 months):
- R = 8.5% ÷ 12 = 0.7083% per month
- EMI = ₹43,391
- Total payment over 20 years = ₹1,04,13,840
- Total interest paid = ₹54,13,840 — more than the loan itself
The Amortisation Schedule: Where Your EMI Goes
What banks rarely show upfront is the amortisation breakdown. In the early years, most of your EMI goes toward interest:
| Year | EMI (Annual) | Principal Paid | Interest Paid | Outstanding Balance |
|---|---|---|---|---|
| Year 1 | ₹5,20,692 | ₹72,320 | ₹4,48,372 | ₹49,27,680 |
| Year 5 | ₹5,20,692 | ₹1,10,244 | ₹4,10,448 | ₹44,91,980 |
| Year 10 | ₹5,20,692 | ₹1,78,440 | ₹3,42,252 | ₹36,68,200 |
| Year 15 | ₹5,20,692 | ₹2,89,620 | ₹2,31,072 | ₹22,84,600 |
| Year 20 | ₹5,20,692 | ₹5,12,348 | ₹8,344 | ₹0 |
The takeaway: in Year 1, only ₹72,320 of your ₹5.2 lakh annual payment reduces the principal. The rest (₹4.48 lakh) is pure interest income for the bank.
Floating vs Fixed Rate — The Real Comparison
| Factor | Floating Rate | Fixed Rate |
|---|---|---|
| Current rates (Jun 2026) | 8.35% – 9.50% | 9.50% – 11.00% |
| EMI stability | Changes with RBI policy | Fixed for loan tenure |
| Prepayment charges | Nil (RBI mandate) | 2% on outstanding |
| Best for | Falling rate environment / short tenure | Rising rate fears / budget-sensitive borrowers |
| Risk | EMI/tenure may rise | Stuck at higher rate if rates fall |
Prepayment: The Most Powerful Lever
A single prepayment of ₹5 lakh in Year 2 of a ₹50 lakh / 8.5% / 20-year loan:
- Tenure reduction option: Saves ~₹18–22 lakh in interest, closes loan ~4 years early
- EMI reduction option: Reduces EMI by ~₹3,800/month
The earlier the prepayment, the larger the saving — because you reduce the base on which compound interest accrues. Use our EMI calculator to model your exact scenario.
Tax Benefits Under Section 24(b) — Old Regime Only
Under the old tax regime, interest paid on a home loan for a self-occupied property is deductible up to ₹2 lakh per year under Section 24(b). For let-out property, the entire interest is deductible against rental income.
Important: These deductions are not available if you opt for the new tax regime (Section 115BAC). For borrowers paying ₹3-5 lakh/year in interest, this can be a significant factor in regime choice.
Affordability Rule of Thumb
Financial planners in India use two benchmarks:
- EMI-to-income ratio: Keep total EMIs below 40% of gross monthly income
- Property value: Loan amount should not exceed 4–5× annual gross income