EMI — Equated Monthly Instalment — is the fixed monthly payment you make to your bank until the home loan is fully repaid. Understanding how it's calculated helps you make smarter decisions about loan tenure, down payment, and prepayment.
The EMI Formula
The standard EMI formula is:
EMI = P × r × (1+r)ⁿ / ((1+r)ⁿ − 1)
Where:
- P = Principal loan amount
- r = Monthly interest rate = Annual rate / 12 / 100
- n = Total number of monthly instalments
EMI Examples at Different Loan Amounts
| Loan Amount | Rate (p.a.) | Tenure | EMI | Total Interest |
|---|---|---|---|---|
| ₹50 Lakh | 8.5% | 20 years | ₹43,391 | ₹54.1L |
| ₹80 Lakh | 8.5% | 20 years | ₹69,425 | ₹86.6L |
| ₹1 Crore | 8.5% | 20 years | ₹86,782 | ₹1.08Cr |
| ₹50 Lakh | 8.5% | 30 years | ₹38,446 | ₹88.4L |
Notice: extending tenure from 20 to 30 years reduces EMI by ₹4,945/month but adds ₹34.3L in total interest paid.
How a 0.5% Rate Change Affects Your EMI
| Interest Rate | EMI (₹50L, 20Y) | Total Interest |
|---|---|---|
| 8.0% | ₹41,822 | ₹50.4L |
| 8.5% | ₹43,391 | ₹54.1L |
| 9.0% | ₹44,986 | ₹57.9L |
| 9.5% | ₹46,607 | ₹61.9L |
A 1% rate increase on ₹50L adds roughly ₹7.5L in total interest over 20 years.
Short Tenure vs Long Tenure
Choosing a shorter tenure is almost always better if you can afford the higher EMI:
- Faster equity build-up: More of each EMI goes to principal early on
- Lower total interest: Often saves 40–50% in interest cost
- Lower risk: Less exposure to rate changes over time
Rule of thumb: your EMI should not exceed 40–45% of net monthly take-home salary.
Prepayment: The Most Powerful Strategy
Making even a small lump-sum prepayment in the first few years dramatically reduces total interest. On a ₹50L / 8.5% / 20Y loan, a ₹5L prepayment in year 2 saves approximately ₹9–12L in total interest and cuts 2–3 years off the loan tenure.