Mortgage calculator
Extra Mortgage Payment Calculator
See how an extra payment could shorten your mortgage.
Built for U.S. financial rules and mortgage conventions.
September 2026
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Understand the estimate
What your result means
The extra amount is modeled as monthly principal, which can reduce future interest and shorten the modeled payoff time.
Confirm with your lender or servicer that extra funds are applied to principal and review any prepayment rules. Extra payments are one option, not a universal best choice.
Important considerations
Before you decide
- Assuming every extra payment is automatically applied to principal.
- Comparing only interest savings without considering liquidity and other financial priorities.
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
Will extra mortgage payments reduce interest?
When applied to principal, extra payments can reduce the balance sooner and therefore the future interest modeled by this calculator.
Should I make extra mortgage payments?
That depends on your loan terms, liquidity, and financial priorities. Confirm lender rules before sending extra funds.