Amortization Calculator with extra payment option
Amortization Calculator
Calculate monthly loan payments and see how extra payments reduce interest and loan term.
Introduction
The Amortization Calculator shows how your loan payments break down over time into principal and interest, and lets you see exactly how much time and interest you can save by adding an extra monthly payment. It's built for anyone with a home, personal, or auto loan who wants to understand — and potentially shorten — their repayment schedule.
How to Use
Enter the following details:
- Loan Amount: The total amount borrowed, e.g., 200000.
- Annual Interest Rate (%): The yearly interest rate on the loan, e.g., 5.5.
- Loan Term (Years): The original repayment period, e.g., 30.
- Extra Monthly Payment: An optional additional amount you plan to pay each month beyond the required EMI, e.g., 200.
Click "Calculate" to see your monthly payment, how much interest you'll pay in total, and — if you entered an extra payment — how much sooner the loan gets paid off and how much interest you save.
Formula/Methodology
Monthly Interest Rate (r) = Annual Interest Rate ÷ 12 ÷ 100
Number of Months (n) = Loan Term (Years) × 12
Base EMI = P × r × (1 + r)n ÷ [(1 + r)n − 1], where P is the Loan Amount
Each month, Interest Portion = Remaining Balance × r, and Principal Portion = (EMI + Extra Monthly Payment) − Interest Portion. The remaining balance is reduced by the Principal Portion each month, and this repeats until the balance reaches zero — which happens sooner when an extra payment is included.
Worked Example
For a loan of ₹2,00,000 at 5.5% annual interest over 30 years, with no extra payment:
Monthly Rate = 5.5% ÷ 12 = 0.4583% = 0.004583
Number of Months = 30 × 12 = 360
Base EMI ≈ ₹1,136 per month, with total interest over 30 years of roughly ₹2,08,900.
Adding an extra ₹200 per month toward principal reduces the loan term to roughly 20–21 years and cuts total interest paid by a significant portion — the calculator shows the exact revised payoff time and interest savings based on your entered figures.
Practical Uses
This calculator is useful for:
- Home loan borrowers in India deciding whether making small extra prepayments each year (common with annual bonuses) can meaningfully shorten their loan tenure.
- Comparing the long-term interest savings of consistent extra payments versus a single lump-sum prepayment.
- Understanding the amortization schedule — how the interest-to-principal ratio shifts over the life of a loan, with more going toward interest in early years.
- Financial planning around loan foreclosure decisions, especially relevant given RBI guidelines that allow floating-rate home loan prepayment without penalty in India.
FAQ
Q1: Is the extra monthly payment field mandatory?
No, it's optional — you can leave it blank to see a standard amortization schedule, or enter a value to see the impact of additional prepayments.
Q2: Does this account for prepayment penalties?
No, the calculator assumes extra payments go entirely toward reducing principal with no penalty; check your loan agreement, as fixed-rate loans in India may carry prepayment charges while floating-rate loans typically do not for individual borrowers.
Q3: How much can extra payments realistically save?
Even a modest extra payment can meaningfully reduce total interest and tenure, especially when started early in the loan, since it directly reduces the principal balance on which future interest is calculated.