The mortgage calculation formula is: 1. Calculation formula of average capital mortgage loan: monthly repayment amount = principal /n+ residual principal * monthly interest rate, with the monthly repayment principal unchanged and the monthly repayment interest decreasing month by month. 2. Calculation formula of mortgage loan with equal principal and interest: monthly repayment amount = principal * monthly interest rate *[( 1+ monthly interest rate) n/[( 1+ monthly interest rate) n- 1], and the monthly repayment amount is the same.

The word "Mortgage" is a Cantonese transliteration of the English word "mortgage", pronounced as à nji. It refers to a loan method of buying a house or shopping by borrowing money from a bank as collateral and then repaying it in installments.