Credit card interest is calculated on a daily basis. Interest = unpaid amount * number of days unpaid * 0.05. Credit card interest will only accrue interest in the case of overdue repayment, minimum repayment, overdraft withdrawal, etc. If You have incurred interest while using your credit card. It is recommended that you repay it in time, because if the credit card interest is not paid off in the current month, compound interest will be calculated next month.