Calculation principle: from the beginning of monthly contribution, the bank collects the interest of the remaining principal first, and then the principal; The proportion of interest in monthly payment decreases with the decrease of residual principal, and the proportion of principal in monthly payment increases with the increase, but the total monthly payment remains unchanged.

Down payment = principal × down payment ratio

Monthly payment = monthly principal+monthly principal and interest

Monthly principal = principal/repayment months

Monthly principal and interest = principal x monthly interest rate

2. Calculation formula of average capital

The borrower distributes the principal equally every month and pays off the interest between the last repayment date and the current repayment date. Compared with the matching principal and interest, the total interest cost of this repayment method is lower, but the principal and interest paid in the early stage are more, and the repayment burden is reduced month by month.

Monthly repayment amount = monthly principal+monthly principal and interest

Monthly principal = principal/repayment months

Monthly principal and interest = (principal-total accumulated repayment) x monthly interest rate

Calculation principle: the amount of principal returned every month is always the same, and the interest will decrease with the decrease of the remaining principal.