A method of calculating interest payments by credit card companies. By this method, the interest computed by billing the card holder not just for 30 days but for 60 days and the total bill is divided in half to calculate the interest owed. For example, if a cardholder made a $100 purchase in June and pays this on the same month, he will still be billed for the $100 in July as the interest is computed for the past 60 days.