Mortgage interest is generally related to loan amount, loan term and loan interest rate, and the calculation formula is: interest = loan amount * term * interest rate. The interest rate for calculating mortgage interest fluctuates on the basis of the benchmark interest rate of the People's Bank of China, and the floating ratio of each bank is not exactly the same. The benchmark interest rate of people's bank loans is as follows:

Commercial loans:

1, with a one-year interest rate of 4.35%;

2. The interest rate for one to five years is 4.75%;

3. The interest rate over five years is 4.90%;

Provident fund loan:

1, with an interest rate of 3.25% within five years;

2. The interest rate over five years is 3.75%.

Interest = loan amount × annual interest rate × term. This formula is calculated as simple interest within the term, and it is a one-time repayment formula. Loans are different. First of all, they are compounded monthly. The second is to repay by installments, and part of the principal repaid is not used for subsequent calculation of interest.

Legal basis: Provisions of the Supreme People's Court on Several Issues Concerning the Application of Law in the Trial of Private Lending Cases.

Article 26:

If the interest rate agreed between the borrower and the borrower does not exceed the annual interest rate of 24%, and the lender requests the borrower to pay interest at the agreed interest rate, the people's court shall support it.

The interest rate agreed between the borrower and the borrower exceeds the annual interest rate of 36%, and the interest agreement in excess is invalid. The people's court shall support the borrower's request to the lender to return the part of the interest paid that exceeds 36% per annum.