The sum of all interest payments to date or over the life or the loan. This is an incomplete measure of the cost of credit to the borrower because it does not include up-front cash payments, and it is not adjusted for the time value of money.

Example

On a standard 30 year fixed $200,000 mortgage, the monthly payment is $1330.06. Over the course of the loan the mortgagee will end up paying $279,017.79 in Cumulative Interest, thus for borrowing $200,000 someone will end up Paying $479,000 over the course of the loan.

To calculate cumulative mortgage on your loan click this handy mortgage calculator.