What Is Loan Amortization? A Complete Guide for Indian Borrowers
What Is Loan Amortization?
Loan amortization is the process of paying off a loan through regular scheduled payments over a fixed period. Each payment covers two things:
- Interest — the cost of borrowing money
- Principal — repayment of the actual amount borrowed
An amortization schedule is a complete table showing how each EMI is split between principal and interest, and what the outstanding balance is after each payment.
Why Does Interest Feel So High at the Start?
This is the most common question from first-time home loan borrowers. The answer lies in how interest is calculated.
Interest is calculated on the outstanding balance. When you take a loan of ₹50 Lakhs, your entire ₹50L is outstanding. So the bank charges interest on the full ₹50L for the first month.
Let’s say your annual rate is 8.5%:
- Monthly rate = 8.5% ÷ 12 = 0.708%
- First month’s interest = ₹50,00,000 × 0.708% = ₹35,417
If your EMI is ₹43,391 (for 20-year tenure):
- Interest portion = ₹35,417 (81.6%)
- Principal repaid = ₹7,974 (18.4%)
By month 200 (nearly the end), the balance has dropped to ~₹2L:
- Monthly interest = ~₹1,400 (just 3.2% of EMI)
- Principal repaid = ~₹41,991 (96.8% of EMI)
This “front-loading” of interest is standard in all amortized loans worldwide.
The Amortization Formula
$$\text{EMI} = \frac{P \times r \times (1+r)^n}{(1+r)^n - 1}$$
Where:
- P = Principal loan amount
- r = Monthly interest rate (Annual rate ÷ 12 ÷ 100)
- n = Tenure in months
How to Read an Amortization Schedule
| Month | EMI | Principal | Interest | Balance |
|---|---|---|---|---|
| 1 | ₹43,391 | ₹7,974 | ₹35,417 | ₹49,92,026 |
| 12 | ₹43,391 | ₹8,574 | ₹34,817 | ₹48,71,582 |
| 60 | ₹43,391 | ₹12,648 | ₹30,743 | ₹43,26,174 |
| 120 | ₹43,391 | ₹19,187 | ₹24,204 | ₹33,99,534 |
| 240 | ₹43,391 | ₹43,087 | ₹304 | ₹0 |
Notice how the interest portion shrinks and the principal portion grows every month.
The Power of Prepayment
Making a lump-sum prepayment is one of the best financial decisions you can make. Here’s why:
Example: ₹50L loan at 8.5% for 20 years
- Total interest without prepayment: ₹54.1 Lakhs
- One-time prepayment of ₹5L after year 5: Interest saved ≈ ₹8–10 Lakhs
The earlier you prepay, the more you save — because you reduce the principal on which future interest is calculated.
Key Takeaways
- Interest is always calculated on the outstanding principal balance
- Early EMIs are mostly interest; later EMIs are mostly principal
- The total interest on a long-tenure loan can exceed the original principal
- Prepayments save a disproportionately large amount in interest
- Use our Loan Amortization Calculator to model your specific loan
Frequently Asked Questions
Can I change my EMI mid-tenure?
Some lenders allow a change (increase or decrease) in EMI under specific conditions. Increasing EMI is called “step-up EMI” and can significantly reduce total interest.
Does part-prepayment reduce EMI or tenure?
Banks typically offer a choice. Reducing tenure is mathematically better (saves more interest), but reducing EMI gives immediate cash-flow relief.
Is interest on home loans tax-deductible?
Yes. Under Section 24(b) of the Income Tax Act, interest paid on a home loan (for a self-occupied property) is deductible up to ₹2 Lakhs per year.