. AT&T 2:46 PM 13% Xtra: Let's say you have a charge of $580 on a credit card. You only plan on paying the minimum which we'll keep at $20 to make life easy for now. Also, you aren't putting any additional charges on it (smart!). What's the amount on the card after a year if the APR is 24%? (You might want to use the table below to help you organize your amounts.) Is it smart to only pay the minimum payment? Will you ever pay it off, if so, about how many years will it take? Some credit cards have the following for calculating the minimum payment: the greater of the following (on top of any fees and charges): (Citi Master Card) The new balance on the billing statement, if it is less than $20 $20 if the new balance is at least $20 1 percent of the new balance plus finance charges and any applicable late fees 1.5 percent of the new balance As you notice, minimum payments can get quite complicated