1. First of all, the installment interest of ICBC's credit card is calculated according to the monthly interest rate. Interest rate is usually given in the form of annual interest rate, which needs to be converted into monthly interest rate.

2. Secondly, ICBC generally sets a fixed number of credit card installments, such as 12 months, 24 months, etc. According to the number of periods selected, the interest to be paid each month will be different.

Finally, the calculation of interest is based on the remaining unpaid amount. The calculation formula of monthly interest rate is: remaining unpaid amount × monthly interest rate.

To sum up, the calculation method of installment interest of ICBC's credit card is the monthly remaining unpaid amount multiplied by the monthly interest rate. The longer the number of installments, the more interest you need to pay each month.

Extended data:

According to the regulations of China Banking Regulatory Commission, commercial banks can charge certain fees in installment payment of credit cards, including installment fees and installment interest. The installment fee is generally charged according to a certain proportion of the number of installments, while the installment interest is calculated according to the above method.

The above is the explanation of the calculation method of installment interest of ICBC credit card. If you have other questions or need further information, please consult the relevant financial institutions of ICBC or consult relevant information.