Many sellers list and sell their properties before inquiring about the cost of discharging their mortgage and find out on the closing date that they will have to pay $5,000, $10,000, $20,000 or even $30,000 to break their mortgage.The amount of the penalty will depend on several factors: whether your mortgage is fixed or variable, how far along you are into the term of the mortgage, the interest rate and the terms of your mortgage contract. The Ratehub Mortgage Penalty Calculator is a tool used to help you determine what your prepayment penalty may be, however, it is always best to call your bank or lender to determine the actual fee.