Mortgage Prepayment Penalty Calculator
Last updated: October 15, 2026
Estimate a possible mortgage prepayment penalty using either months of interest or a percentage of the remaining loan balance.
Estimated prepayment penalty
—
- 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.
Read the complete guide
Updated reference sections in this guide are in English.
What this calculator estimates
Estimate a possible mortgage prepayment penalty using either months of interest or a percentage of the remaining loan balance.
How to use it
Enter Remaining mortgage balance ($); Annual interest rate (%); Penalty method; Months of interest; Balance penalty (%). Select Calculate to update the results.
How the calculation works
The calculator displays two common estimate methods: a selected number of months of interest and a percentage of the remaining principal balance.
Worked example: starting scenario
| Remaining mortgage balance ($) | 325000 |
|---|---|
| Annual interest rate (%) | 6.25 |
| Penalty method | Months of interest |
| Months of interest | 6 |
| Balance penalty (%) | 2 |
| Estimated prepayment penalty | $10,156.25 |
|---|---|
| One month of interest | $1,692.71 |
| Penalty using months-of-interest method | $10,156.25 |
| Penalty using balance-percentage method | $6,500.00 |
| Remaining balance after penalty is added | $335,156.25 |
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.