Extra Payment Calculator
Test whether sending extra money each month meaningfully shortens payoff time before you commit to it.
Calculator
Extra Payment Calculator
Enter the loan balance you want to pay down faster.
Use the annual rate on the loan.
Enter the amount you normally pay each month.
Add the recurring extra amount you may pay each month.
Example values are loaded.
Result
Your result
Adding $250.00 per month would shorten payoff by about 8 years 3 months and save roughly $108,124.41 in interest.
Time saved
8 years 3 months
Interest saved
$108,124.41
New payoff time
21 years 7 months
Plan comparison
Next steps
Compare before you move on
Most people use one calculator to answer the first question and a related tool to pressure-test the decision.
Borrowing
Loan Calculator
Estimate monthly loan payments, total interest, and total repayment with a standard amortized loan formula.
Borrowing
Refinance Calculator
Compare current mortgage payments with a refinance scenario and estimate monthly savings, total cost, and break-even based on how closing costs are handled.
Debt
Debt Payoff Calculator
Estimate how long it could take to eliminate a balance based on your interest rate and monthly payment.
What this calculator shows
Extra payments feel small in the moment, but on a large balance they can remove months or years of interest because principal falls earlier.
This calculator compares the current payoff path with an accelerated plan so you can see whether the extra payment is worth the squeeze in your monthly budget.
How to use it
- 1. Enter the current balance and interest rate on the loan.
- 2. Add the regular monthly payment you already make.
- 3. Test an extra monthly payment to compare time saved and interest saved.
Formula and assumptions
The payoff path is simulated month by month by applying interest to the remaining balance and then subtracting the payment amount.
The comparison uses the same balance and rate for both the regular plan and the accelerated plan with the extra monthly payment.
Notes
This assumes the lender applies the extra payment directly to principal and that the rate stays fixed.
Worked example
An extra few hundred dollars per month on a large balance can cut years off the payoff window depending on the rate.
This example uses the default sample inputs loaded on reset. It does not update with the live calculator entries above.
Time saved
8 years 3 months
Interest saved
$108,124.41
New payoff time
21 years 7 months
Feedback
Found a problem on this page?
Report confusing fields, broken math, or missing assumptions with the exact inputs you used so the issue can be reproduced.
FAQ
FAQ
Does every lender apply extra payments to principal the same way?
No. Some loans require a specific instruction or separate principal-only payment, so confirm the lender's process before relying on the estimate.
FAQ
Why can a small extra payment save so much interest?
Because reducing principal earlier lowers the balance on which future interest is calculated, which compounds the benefit over time.