The calculation of overdue interest on bank loans cannot exceed the principal. According to Chinese banking regulations, banks will use the overdue principal as the basis when calculating overdue interest, and calculate interest based on the interest rate stipulated in the contract. The following is a detailed explanation of this issue:

1. Calculation basis of overdue interest: When banks calculate overdue interest, they will use the overdue principal as the basis. Overdue principal refers to the unpaid principal amount, that is, the loan amount minus the principal that has been repaid.

2. Interest rate agreement: According to the loan contract, the bank will clearly stipulate the overdue interest rate, that is, the calculation ratio of interest. Overdue interest rates are usually higher than normal interest rates to encourage borrowers to repay on time.

3. Calculation method of overdue interest: Overdue interest is calculated on a monthly or daily basis and is calculated based on the overdue interest rate stipulated in the contract. For example, if the overdue interest rate is 2% per month and the overdue principal is 10,000 yuan, the monthly overdue interest is 10,000 yuan times 2%.

To sum up, the calculation of overdue interest on bank loans cannot exceed the principal. The basis for calculating overdue interest is the overdue principal, which is calculated based on the overdue interest rate stipulated in the loan contract. The bank will calculate the actual overdue interest based on the overdue principal and overdue interest rate. Therefore, overdue interest will not exceed the principal.

Extended information:

According to relevant laws and regulations in China, banks have certain restrictions on charging overdue interest and cannot charge high fees without limit. In addition, banks will also take a series of measures to recover overdue loans, such as delinquency information records, collection notices, legal procedures, etc. Therefore, borrowers need to make timely repayments to avoid overdue interest.

Please note that the above information is for reference only and is not a reference to specific legal provisions. Specific situations should be judged and handled according to the laws and regulations of the individual's location and the provisions of the bank contract. It is recommended that borrowers communicate and negotiate with banks on the basis of understanding relevant laws, regulations and contractual agreements.