A loan prepayment calculator needs a handful of details about your existing loan to simulate what happens if you pay extra towards it. Here's what each input means and how to read the results, using the calculator on this site as the example.
Step 1: Enter your loan type and current outstanding principal
Select your loan type (home, personal, car, education or other) and enter your current outstanding principal - not your original loan amount. This is the balance you still owe today, which you can find on your latest loan statement or your lender's app. Using the original loan amount instead of the current balance will significantly overstate your remaining interest.
Step 2: Enter your interest rate and current EMI
Enter your loan's current annual interest rate and your current EMI (payment amount). If your loan is on a floating rate, use the rate that applies today - the calculator assumes it holds steady for the remaining term, so treat results as a snapshot based on current conditions rather than a fixed prediction.
Step 3: Enter your remaining tenure
Enter how much time is left on your loan, in years and months - again, the remaining time, not the original loan tenure.
Step 4: Enter a prepayment amount and frequency
Enter how much extra you plan to pay, and how often: a one-time lump sum, or a recurring monthly, quarterly or yearly extra payment. If you're not sure yet, start with a one-time amount to see the effect of a single lump sum.
Step 5: Read the results
The calculator shows two scenarios side by side: what happens with no prepayment at all, and what happens with your prepayment applied. Look specifically at:
- New tenure - how much sooner the loan would be paid off.
- Interest saved - the total interest avoided by prepaying, compared to not prepaying.
- New estimated closing date - when the loan would actually end.
Step 6: Compare different prepayment amounts
Use the comparison view to see several preset amounts side by side - for example ₹50,000, ₹1,00,000 and ₹2,00,000 - plus your own custom figure, so you can judge whether a larger prepayment is worth committing more of your savings to, or whether a smaller amount already captures most of the benefit.
Key takeaways
- Always use your current outstanding principal and remaining tenure, not the original loan figures.
- The calculator assumes your current interest rate holds for the rest of the term - treat results as a snapshot, especially for floating-rate loans.
- Compare a few different prepayment amounts before committing to see how the saving scales.
- Confirm final figures with your lender, since exact interest-application conventions can vary slightly.
Try it with your own numbers
Takes under a minute - no login, nothing saved on a server.
Frequently asked questions
What if I don't know my exact outstanding principal?
Check your most recent loan statement or your lender's mobile app/net banking portal - outstanding principal is usually shown clearly. It's different from your original loan amount, which is only a starting reference point.
Why might the calculator's numbers differ slightly from my bank's figures?
This calculator runs a full month-by-month amortization simulation, the same method most lenders use internally. Small differences usually come from your lender's exact interest-application date, compounding convention, or fees - always confirm final figures with your lender.
Can I compare more than one prepayment amount?
Yes - the calculator's comparison view shows several preset amounts side by side (such as ₹50,000, ₹1,00,000 and ₹2,00,000) plus your own custom amount, so you can see how the interest saved scales with the size of the prepayment.