Sharing: It is common in our life to introduce the collection recommendation of loans. In fact, you spent money today, and you have to pay interest on it. Naturally, how much interest you pay is your natural concern. Here, several mortgage loan models are established to discuss the calculation formulas of total repayment amount, total interest and annuity respectively, so as to provide reference for borrowers to formulate reasonable loan plans. 1 Equal principal and interest repayment method The equal principal and interest repayment method is to add up the total amount of mortgage principal and interest, and then distribute it evenly to each month during the repayment period. The repayment person pays a fixed amount to the bank every month, with the proportion of principal increasing month by month and the proportion of interest decreasing month by month. Set the loan principal p point. Repayment, interest rate:, a is annuity. Once every few years, the present value of the first phase of the final annuity is green, the present value of the second phase of the final annuity is l+ property, and so on. After deducting the interest of each period, the annuity incurred at the end of each period is converted into the present value, and the accumulated total loan amount is =A, then the annuity paid in each period is = r(l+:)n (l+r)n-L, and the total repayment amount is s=nA, which is (l+r) for plastic industry. The average capital repayment method and the average capital repayment method mean that the borrower repays the loan principal in equal amount every month and repays at the same time.