What Is Loan Amortization?
Loan amortization is the process of repaying a loan through fixed periodic payments (EMIs) where each payment covers both the interest on the outstanding balance and a portion of the principal, until the loan balance reaches zero at the end of the term.
Every EMI-based loan in India uses an amortization structure. The key characteristic is that while the EMI amount stays the same throughout the loan term, the split between principal and interest changes with every payment. In the early months, most of the EMI goes toward interest because the outstanding loan balance is at its peak. As the balance reduces, the interest portion shrinks and more of the EMI goes toward principal reduction.
An amortization schedule is the complete table showing this breakdown for every payment across the full loan term. It includes the payment number, the principal portion, the interest portion, and the remaining balance after each payment. This schedule is the single most useful tool for understanding the true cost of a loan and planning prepayments.
Loan Amortization Formula
The EMI for an amortizing loan is calculated using the standard reducing-balance formula:
EMI = [P x R x (1+R)^N] / [(1+R)^N - 1]
| P | Principal loan amount (the total amount borrowed) |
| R | Monthly interest rate = Annual rate / 12 / 100 |
| N | Loan tenure in months (years x 12) |
Worked example
For a Rs 10 lakh loan at 9% for 5 years (60 months):
R = 9 / 12 / 100 = 0.0075
N = 5 x 12 = 60
EMI = [10,00,000 x 0.0075 x (1.0075)^60] / [(1.0075)^60 - 1]
EMI = Rs 20,758 per month
Over 60 months, total repayment is Rs 12,45,480. Of this, Rs 10,00,000 is the principal and Rs 2,45,480 is the total interest cost. The amortization schedule above shows how each of the 60 payments is split.
Understanding the Amortization Schedule
The amortization schedule reveals a crucial pattern: in the early years of a loan, a disproportionately large share of each EMI goes toward interest. This happens because the outstanding principal is at its maximum, and interest is calculated on this balance each month.
For the Rs 10 lakh loan at 9% for 5 years, the first EMI of Rs 20,758 comprises approximately Rs 7,500 in interest and only Rs 13,258 in principal. By the final payment, the split flips to roughly Rs 154 in interest and Rs 20,604 in principal. The bar chart in the amortization section of this calculator shows this progression visually for your exact inputs.
Understanding this pattern is important for planning prepayments. A lump-sum prepayment in the first half of the loan term, when the interest component is still large, produces proportionally greater savings than the same payment made later. The schedule also reveals how much total interest you will pay: information that many borrowers do not realise until they see it laid out year by year.
Factors Affecting Amortization
Three variables determine how your amortization schedule looks and how much total interest you pay over the loan term.
Loan amount (principal)
A larger loan means a higher EMI and more total interest. Every Rs 1 lakh increase in loan at 9% for 5 years adds roughly Rs 2,076 to the monthly EMI and approximately Rs 24,548 in total interest over the loan term.
Interest rate
A 0.5% increase in rate on a Rs 10 lakh, 5-year loan adds approximately Rs 540 to the monthly EMI and about Rs 32,400 to total interest. Even small rate differences compound significantly over longer tenures. This is why balance transfers to a lower rate can save substantial amounts when more than half the tenure remains.
Loan tenure
Extending tenure from 3 years to 5 years on a Rs 10 lakh loan at 9% drops the EMI from Rs 31,800 to Rs 20,758. However, total interest jumps from Rs 1.45 lakh to Rs 2.46 lakh. Extending to 7 years drops the EMI further to Rs 16,105 but total interest rises to Rs 3.53 lakh. Shorter tenures hurt the monthly budget but save substantially on the total cost of borrowing.
Extra payments and prepayment
Any additional payment beyond the scheduled EMI directly reduces the outstanding principal. This reduces the interest calculated in subsequent months and shortens the remaining term. Per RBI guidelines, most floating-rate loans in India carry no prepayment penalty, making early repayment one of the most effective ways to reduce the total cost of a loan.
How to Use This Loan Amortization Calculator
- Enter loan amount: Use the slider to set the total amount you plan to borrow. You can enter values from Rs 50,000 to Rs 5 crore. Click the displayed value to type a precise number.
- Set interest rate: Enter the annual interest rate offered by your lender. The slider covers the full range from 1% to 30% per annum, covering home loans, personal loans, car loans, and education loans.
- Choose tenure: Select your loan repayment period in years or months. Use the year presets (1Y, 3Y, 5Y, 10Y, 15Y, 20Y, 30Y) to quickly compare how different tenures affect your EMI and total interest.
- View the amortization schedule: The calculator shows your monthly EMI, total interest payable, and total amount payable. Click "Amortization Schedule" to expand the full year-by-year breakdown with the stacked bar chart and data table.
Frequently Asked Questions
Disclaimer: All calculations on this page are indicative only and based on the inputs provided. EMI figures, interest totals, and amortization schedules are mathematical approximations and may differ from actual lender calculations due to rounding, processing fees, GST on charges, and lender-specific policies. Interest rates shown are indicative as of June 2026 and subject to change. This tool is for educational and planning purposes only and does not constitute financial or legal advice. Consult a SEBI-registered investment adviser or a qualified CA before making financial decisions.