Monthly repayment amount = (loan principal × monthly interest rate× (1+monthly interest rate) total repayment period) /( 1+ monthly interest rate) total repayment period-1.
Average capital repayment method: it is a kind of diminishing repayment method. Using this method, the loan principal is divided into several repayment periods, and the interest payable in each period is calculated from the unpaid principal. The principal amount of each period is unchanged, and the interest is decreasing step by step. The calculation formula is as follows:
Monthly (quarterly) repayment amount = loan principal/repayment times+(loan principal-accumulated amount of repaid principal) × monthly (quarterly) interest rate.
In the average repayment method, the repayment amount of each installment is different. At first, due to the large principal, interest and monthly payment. With the continuous reduction of principal, interest and monthly payment also decrease.
Monthly repayment amount = current principal repayment+current interest.
Current month's repayment amount = total loan amount ÷ repayment times.
Current month's interest = last month's remaining principal × monthly interest rate
= total loan × (1- (repayment months-1)÷ repayment times )× monthly interest rate.
Total interest = total loan amount × monthly interest rate × (repayment times+1) ÷ 2