Mortgage Prepayment
See how a lump-sum prepayment impacts your mortgage EMI, total interest, and loan term. Compare original vs revised payoff with free charts and amortization.
About This Calculator
The Mortgage Prepayment Calculator shows you how a one-time lump-sum payment toward your mortgage principal affects your monthly payment, total interest, and payoff timeline. Whether you've received a bonus, inheritance, or tax refund, this calculator helps you decide the best way to apply it to your mortgage.
The calculator compares your original amortization schedule against a revised schedule after the lump-sum prepayment. You can choose between two strategies: keeping the same EMI to shorten the loan term, or reducing the EMI to keep the original tenure. The results show interest saved, time saved, and a balance-over-time comparison chart.
How lump-sum prepayment works
When you make a lump-sum payment, it reduces the outstanding principal balance. Since monthly interest is calculated on the remaining balance, a lower balance means less interest accrues each month going forward. If you keep the same EMI, more of each payment goes toward principal, accelerating the payoff. If you reduce the EMI, your monthly outflow decreases but the loan term stays the same -- you still save interest compared to the original plan.
Regional Notes
India: Home loan interest rates (8-9% as of 2025) make prepayments very attractive. Most banks allow penalty-free prepayment on floating-rate loans. Consider the tax benefit under Section 24 (up to ₹2 lakh) when deciding whether to prepay.
United States: Mortgage rates of 6-7% mean prepayments can save significant interest, especially in the early years. Many conventional loans have no prepayment penalty. The mortgage interest deduction may slightly reduce the effective benefit of prepaying.
United Kingdom: With mortgage rates at 4-5.5%, prepayments still offer meaningful savings. Many fixed-rate deals cap penalty-free overpayments at 10% of outstanding balance per year, so check your mortgage terms before making a large lump-sum payment.
Frequently Asked Questions
What is a mortgage prepayment and how does it save money?
A mortgage prepayment is a lump-sum payment made toward your principal balance ahead of schedule. By reducing the outstanding principal, all future interest charges decrease because interest is calculated on a smaller balance. This lowers the total interest paid over the life of the loan and can shorten your repayment term by years.
What is the difference between mortgage prepayment and extra monthly payments?
Mortgage prepayment refers to a one-time lump sum payment made at a specific point in the loan term, while extra monthly payments are recurring additional amounts added to each month's EMI. This calculator models a lump-sum prepayment -- you specify the month and amount. For recurring extra payments, use our Mortgage Extra Payments calculator. Both strategies reduce interest, but lump sums work well for bonuses or windfalls.
Should I keep the same EMI or reduce EMI after prepayment?
Keeping the same EMI after a prepayment shortens your loan term and saves the most interest. Reducing the EMI keeps the original tenure but lowers your monthly outflow, which helps if you need cash flow relief. Use the toggle in this calculator to compare both strategies side by side and choose what fits your financial goals.
Are there prepayment penalties for lump-sum payments?
Yes, some lenders charge prepayment penalties. In India, most banks allow penalty-free prepayment on floating-rate home loans but may charge on fixed-rate loans. In the US, many conventional loans have no prepayment penalty, but some charge 1-2% of the outstanding balance if prepaid within the first 3-5 years. In the UK, fixed-rate deals often cap overpayments at 10% of outstanding balance per year without penalty. Always check your loan agreement.
When is the best time to make a mortgage prepayment?
Earlier prepayments save more interest because the outstanding balance is larger and more interest accrues each month. The first half of the loan term offers the greatest savings. Even one prepayment early in the loan can reduce the term by several years and save tens of thousands in interest, depending on the amount and interest rate.
Is it better to invest or prepay my mortgage?
Compare your mortgage interest rate with expected after-tax investment returns. If your mortgage rate (e.g., 8-9% in India) exceeds what you can earn from low-risk investments (4-5% FDs in India), prepaying makes financial sense. In the US with a 3-4% mortgage rate, investing in diversified index funds may yield better long-term returns. Consider your emergency fund, tax situation, and retirement goals before deciding.
Does mortgage prepayment affect my credit score?
Making a lump-sum prepayment does not directly hurt your credit score. Lower outstanding balances improve your credit utilization ratio, which can boost your score. However, paying off a mortgage early may cause a slight temporary dip because it reduces your credit mix and average account age. This effect is typically small and short-lived.
How does region detection work in this calculator?
The calculator detects your region (India, US, or UK) from your browser timezone and displays the appropriate currency symbol (₹, $, £). Default loan amounts, interest rates, and tenures are pre-filled with region-specific values. The amortization formulas are universal and apply to any currency.