Mortgage Prepayment Penalty Calculator
Last updated: July 2026
Estimate a possible mortgage prepayment penalty using either months of interest or a percentage of the remaining loan balance.
Estimated prepayment penalty
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- One month of interest: —
- Penalty using months-of-interest method: —
- Penalty using balance-percentage method: —
- Remaining balance after penalty is added: —
On this page
Quick summary: Estimate a possible mortgage prepayment penalty using either months of interest or a percentage of the remaining loan balance. Enter the requested values, calculate, review the result, and compare more than one realistic scenario before making a decision.
Read the complete guide
What this calculator estimates
Estimate a possible mortgage prepayment penalty using either months of interest or a percentage of the remaining loan balance. It is designed for fast planning and comparison in the United States. The output is an estimate, not a binding quote, approval, tax determination, insurance offer or professional recommendation.
How to use it
Enter the requested values using a single consistent time period and currency. Select Calculate, review the headline result and supporting figures, then change one assumption at a time to compare another scenario.
How the calculation works
The calculator displays two common estimate methods: a selected number of months of interest and a percentage of the remaining principal balance.
Important limitations
Your note and applicable law control whether a penalty exists and how it is calculated. Some loans have declining schedules, exceptions or no penalty. Review the actual loan documents.
Frequently asked questions
Is the result exact?
No. It is a planning estimate based on the assumptions entered.
Can I compare different scenarios?
Yes. Change one input at a time so you can see which assumption changes the result.
Does the calculator store my inputs?
The calculation runs in the browser and does not require an account. Avoid entering unnecessary confidential information.