What is exactly total debt interest per U.S. citizen and in what measures it could be understood? According to this debt clock total debt for an average U.S. family is 748,000 and total debt interest per citizen is 9,063. What makes 36+ thousands per 4 person family. 36 thousands of USD to pay as an interest per year make it a huge number. Do you think it is believable? U.S. National Debt Clock : Real Time