Monthly payment: The total amount owed to the lender throughout the course of the loan, paid each month. Each payment has a portion allocated to interest and a remainder to principle. The entire principal that you are borrowing. Your loan calculator will be matched.Total interest payments: The total amount of interest only that you will pay for the duration of the loan. Total interest paid on the loan is equal to the principal amount plus interest. Date of payoff: The last day you'll make loan ...