About the Extra Payment Calculator
See how extra monthly payments shorten a loan, mortgage or credit card and how much interest you save.
Also known as: prepayment calculator, pay off loan early, mortgage overpayment, additional principal payment.
How to use this calculator
- Enter current balance, interest rate, remaining term, extra per month.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
Extra goes straight to principal, cutting future interest
Worked example
Using the values pre-filled in the calculator above:
- Current balance = 250,000
- Interest rate = 6.5 %
- Remaining term = 25 years
- Extra per month = 200
the calculator returns:
- Interest saved: 64,927.88
- Time saved: 5 yr 6 mo
- New payoff time: 19 yr 6 mo
- Regular payment: 1,688.02