The typical American consumer will fork over an average of $279,002 in interest payments during the course of his or her lifetime. So says a new report from Credit.com, which analyzed the lifetime cost of debt in all 50 states and the District of Columbia, based on average mortgage balances, credit card debt, and credit scores. The size of the nut varies dramatically from state to state. Residents of Washington, D.C.—where average new mortgages are $462,000 and the average credit score of 656 falls squarely in the “fair” range—can expect to pay $451,890 in interest, the highest in the nation. Concerned D.C. residents might want to consider hitching a ride to Iowa, where the average new mortgage is the nation’s lowest, at $120,467. Add in an average credit card debt of $2,935—also the lowest in the country—and a credit score of 689, and residents of the Hawkeye State have a lifetime cost of debt of “only” $129,394. Along with 30-year fixed-rate mortgages, Credit.com also considered an average auto loan balance of $22,750 (assuming nine cars over a lifetime) and 40 years of revolving credit card debt when calculating its findings. Here’s a breakdown of the top 10 states with the highest cost of debt: Washington, D.C. ($451,890) California ($368,745) Hawaii ($312,747) New Jersey ($309,500) New York ($300,031) Maryland ($294,720) Virginia ($280,516) Washington ($267,964) Massachusetts ($261,220) Colorado ($255,232) And the lowest: Iowa ($129,394) Nebraska ($137,174) Wisconsin ($144,127) Maine ($154,340) North Dakota ($157,011) South Dakota ($157,136) Montana ($160,849) Pennsylvania ($163,513) West Virginia ($166,232) Vermont ($167,042) See the full state-by-state list.