Loan Prepayment Calculator
LoanCalculate how much interest you save and how many months you cut by prepaying your home or personal loan. Compare lumpsum vs extra EMI prepayment strategies.
Reviewed by the thecalcu.com team Ā· Last updated 26 July 2026
Loan Details
What is a Prepayment?
A Loan Prepayment Calculator shows exactly how much interest you save and how many months you cut off your loan by making payments beyond the scheduled EMI, whether as a single lumpsum or as an increased monthly contribution. It simulates your loan month by month, applies the prepayment at the point you specify, and delivers a precise before-and-after comparison of total interest, total payment, and remaining tenure.
Home loans are the largest financial commitment most Indians make. A ā¹60 lakh home loan at 8.5% for 20 years accrues ā¹64.5 lakh in total interest, meaning you pay more in interest than the principal itself. This is the defining characteristic of long-tenure reducing-balance loans: early years are almost entirely interest, with principal reduction accelerating only in the final years. A targeted prepayment disrupts this curve dramatically.
When you prepay ā¹5 lakh in month 12 of a 20-year loan, that ā¹5 lakh would otherwise have generated approximately 19 years of interest charges. Eliminating it early creates a cascading effect, every subsequent month's interest is computed on a lower balance, creating compounding savings that far exceed the prepayment amount itself. The Loan Prepayment Calculator makes this effect visible with exact numbers.
India's banking regulator (RBI) has eliminated prepayment penalties on floating-rate home loans, removing the last friction from this strategy. Any surplus from a salary bonus, matured FD, or annual appraisal hike can now be directed toward the loan without cost. Understanding the interest saving before acting on a prepayment decision is what this calculator enables. Pair it with the EMI Calculator for the full picture of your home loan economics, or use the Loan Amortization Calculator to see the full month-by-month schedule.
Why Use a Loan Prepayment Calculator?
Quantify the decision before acting. A ā¹2 lakh prepayment may save ā¹4 lakh in interest or ā¹1.5 lakh depending entirely on when in the tenure it is made. The calculator tells you exactly which scenario you are in before you make the transfer.
Compare lumpsum vs. extra EMI. Not all prepayment cash is available as a lump sum. The calculator shows whether paying ā¹10,000 extra per month produces more or less savings than a single ā¹1.2 lakh annual lumpsum, letting you match your prepayment strategy to your actual income pattern.
Optimise bonus and windfall deployment. When a year-end bonus arrives, the choice between prepayment, investment, and spending has a clear financial answer. The interest saved (guaranteed) versus investment return (uncertain) can be compared concretely with this calculator.
Track progress toward loan closure. As your income grows over the years, systematically increasing your prepayment commitment accelerates payoff. The calculator helps you set a goal, closing in 12 years instead of 20, for example, and work backward to the required annual prepayment.
Who Should Use This Calculator?
Home loan borrowers in the first 10 years of repayment get the most benefit from prepayment; this calculator helps them see how much each bonus or surplus can save.
Salaried professionals receiving annual bonuses who want to know whether this year's increment should go toward the loan, a mutual fund SIP, or an FD, the guaranteed interest saving provides a return benchmark for comparison.
NRI borrowers holding a home loan in India while earning abroad can use the calculator to determine the most tax-efficient year to make a large lumpsum from foreign income, given exchange rate timing and remittance costs.
People refinancing or balance-transferring their loan can model the impact of the lower interest rate plus any prepayment they make at the time of the transfer, to arrive at actual savings versus the balance transfer cost.
What Insights Does the Loan Prepayment Calculator Give You?
Months Saved is the primary output, the number of months by which your loan closes earlier. For a 20-year loan, prepayments of 5ā10 lakh can save 30ā60 months, meaning the loan effectively becomes a 15ā17 year loan.
Interest Saved is the rupee amount of cumulative interest eliminated, this is money that would have left your pocket over the remaining tenure and now stays with you. It is typically 1.5ā3Ć the prepayment amount for early-tenure prepayments.
New Tenure and New Total Interest show the revised loan economics after prepayment, making the comparison concrete and shareable with a spouse or financial adviser.
Before/After Comparison presents both scenarios side by side, original EMI, original total interest, and total payment versus the new figures, for a clear view of the full cost of inaction.
How to use this Prepayment calculator
- Enter Outstanding Loan Amount, use your current outstanding balance, not the original loan amount. Find this on your latest bank statement or netbanking portal under "outstanding principal."
- Set Annual Interest Rate, use your current floating rate (check your loan account statement for the exact rate applicable today).
- Set Remaining Tenure, the number of months left on your loan. For a 20-year loan taken 3 years ago, this is approximately 204 months.
- Choose Prepayment Type, select "One-time Lumpsum" if you have a fixed amount ready to pay, or "Extra Monthly Amount" if you plan to increase your EMI.
- Enter Prepayment Amount, the lumpsum amount, or the extra monthly amount above your current EMI.
- For Lumpsum: set Prepayment Month, the month number (from today) at which you plan to make the payment. Month 1 = this month; Month 12 = one year from now.
- Read the savings, the result shows months saved, interest saved, and the full before/after comparison.
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Formula & Methodology
EMI Formula: EMI = P Ć r Ć (1+r)āæ / ((1+r)āæ ā 1) Where P = outstanding principal, r = monthly interest rate (annual rate Ć· 12 Ć· 100), n = remaining months. Prepayment Simulation (month-by-month): For each month: Interest = Outstanding Balance Ć r; Principal Paid = EMI ā Interest; Balance = Balance ā Principal. At prepayment month (lumpsum): Balance = Balance ā Prepayment Amount. For extra EMI: Monthly Payment = EMI + Extra Amount each month. Loop continues until balance reaches zero. Total months = new tenure; Total interest = sum of all monthly interest payments. Worked example: A Bengaluru IT professional has an outstanding home loan of ā¹45 lakh at 8.5% with 18 years (216 months) remaining. - Current EMI = ā¹45,00,000 Ć (0.00708) Ć (1.00708)²¹ⶠ/ ((1.00708)²¹ⶠā 1) = ā¹39,914/month - Original total interest (without prepayment) = ā¹39,914 Ć 216 ā ā¹45,00,000 = ā¹41,61,424 She receives a ā¹3 lakh annual bonus and decides to prepay in month 12. - After simulation with ā¹3 lakh lumpsum at month 12: - New tenure: 192 months (24 months saved = 2 years) - New total interest: ā¹35,18,000 (approximately) - Interest saved: ā¹6,43,000 on a ā¹3 lakh prepayment, a 2.14Ć return, guaranteed If she instead adds ā¹5,000/month (ā¹25,000 extra per quarter equivalent): new tenure ā 183 months, interest saved ā ā¹9.2 lakh over the loan life.
Frequently Asked Questions
What is a loan prepayment and how does it save money?
Which saves more interest, lumpsum prepayment or extra monthly EMI?
When is the best time to make a lumpsum prepayment?
Does prepayment affect the EMI or the loan tenure?
Are there prepayment charges on home loans in India?
How much should I prepay on my home loan each year?
Should I invest a windfall or use it to prepay my home loan?
How does the Loan Prepayment Calculator work?
What is the difference between part-payment and foreclosure?
Can I use this calculator for personal loans or car loans?
How does prepayment interact with the tax deduction on home loan interest?
Planning this?
This calculator is step 5 of 5 in our Home Buying Planner.