mortgage early repayment calculator -- nothing leaves your browser
Add a property and mortgage to get started
Go to the Mortgages tab to add a mortgage, or load a saved file.
Split/Equity Mode Active:
Set the owner's share (%) of each property's equity. E.g., if partner owns 50% of her property, set Owner Share = 50%.
New Property Purchase:
Payment Details
Combine into New Mortgage
Early Repayment Charge (ERC) Rules:
* Annual Overpayment Allowance (AOA): Typically 10% of outstanding balance
* Allowance renews annually on fixed-rate start date
* ERC applies only to amounts over the allowance
* ERC = 1% of overpaid amount x years remaining in fixed period (reducing daily)
* Maximum ERC: 5% of the overpayment amount (above allowance)
Net Benefit Analysis: ERC Cost vs Interest Savings
Per-Property Analysis
Net benefit analysis for each property showing when remortgaging becomes profitable.
Total Repayment Cost Over Time
ERC "Waste" by Repayment Month
Month
Total Balance
Total Interest
Total Principal
Total ERC
Monthly Savings
Net Benefit
Deposit Available
sm.mortgage
A mortgage early repayment and remortgage calculator.
Enter your mortgage details to see your repayment schedule
Model early repayment scenarios and see the savings
Check early repayment charges (ERCs) against your savings
Compare remortgage options side by side
All calculations run in your browser — nothing is stored