Mortgage calculator
Extra Mortgage Payment Calculator
See how an extra payment could shorten your mortgage.
Last reviewed
September 2026
September 2026
Enter your details
Results update privately in your browser.
How we calculate
A transparent estimate you can inspect.
Formula
Two amortization schedules are compared: current payment and current payment plus the extra amount.
Privacy
Your values are calculated locally and are not sent to a server by this calculator.
Use with care
Results are for informational purposes, not financial, tax, legal, lending, or investment advice.
Understanding your results
Interest and time saved compare the original payment with the payment plus extra principal.
Assumptions and limitations
- Extra payment is applied monthly to principal.
Common questions
Before you decide
Does this include every home cost?
No. Review the included fields and plan separately for maintenance, closing costs, and PMI where relevant.
Is this a loan offer?
No. It is an estimate, not lending or financial advice.