If the shopper spent $1,054, and paid a minimum payment of $25 each month, he or she would be paying down that balance until 2023. With an average interest rate of 15.9 percent, according to a MagnifyMoney analysis, fees on that debt could add up to $500. In August 2017, Americans hit the highest amount of credit card debt in US history, at $1.021 trillion in outstanding revolving credit in June 2017.