Suppose your total mortgage is 340,000 yuan, the loan term is 10 year, and the interest rate is 5% (assuming a fixed interest rate here), then the monthly repayment amount can be calculated by the formula of equal principal and interest repayment:

Monthly repayment amount = (principal x monthly interest rate x (1+ monthly interest rate) repayment months) /(( 1+ monthly interest rate) repayment months-1)

Among them, the principal is the total amount of mortgage, the monthly interest rate is the annual interest rate divided by 12, and the number of repayment months is the loan period multiplied by 12 (because it is a monthly repayment).

Substitute the data to get:

Monthly interest rate = 5%/ 12 = 0.004 17.

Number of repayment months =10x12 =120.

Monthly repayment amount = (340,000 x 0.00417x (1+0.00417)120)/(1+0.00417)/

Therefore, you need to repay 3985.32 yuan every month.