Mortgage calculation formula

Definition: When buying a house with an equal principal and interest loan, the formula for calculating the monthly repayment amount is: [loan principal × monthly interest rate ×( 1 interest rate )× repayment months ]≤[( 1 interest rate )× repayment months-1] Calculation principle: the bank first collects the interest on the remaining principal from the monthly contribution, and then collects it. 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.