Cities with the biggest, smallest credit card debt burdens

San Franciscans aren't known for their frugal lifestyles. But residents of northern California's digital mecca carry the lightest credit card debt burden of any major metropolitan area in the nation, an analysis by CreditCards.com found.

The average Bay Area resident had a card balance of $4,393 in 2014, a whisker under the U.S. average of $4,410. But when you consider income, the typical working resident could pay that off in nine months -- the quickest payback in the 25 largest U.S. cities. That's assuming they devote $533 a month -- 15 percent of their comfortable earnings -- to paying the debt.

"High income means creditworthiness," Comerica Bank Chief Economist Robert Dye said. "People are going to be comfortable carrying more debt."

On other end of the spectrum, San Antonio consumers faced the longest time to pay off card debt. Their card balances averaged $4,880, or $470 more than the U.S. average. With an overall lower income, it would take the typical resident 16 months to wipe that out, paying $344 a month. The interest cost during payback would be $448 -- almost double the $234 cost in San Francisco.

Our analysis
CreditCards.com looked at the balance on the average person's credit cards in the 25 largest U.S. metro areas, based on credit report data from credit bureau Experian. The time it takes to pay that balance was calculated using 15 percent of the median earnings for each city, according to Census Bureau figures. Fifteen percent of earnings is a rule of thumb used by some credit counselors to evaluate debt repayment plans.

Cities are ranked by the number of months to pay off the debt. When cities tie for number of months, they are ranked by how much interest would pile up during the payoff period, at a typical 13 percent rate.

Result: The places with light debt loads are not the ones you might think. The parsimonious Midwest boasts a pay-as-you-go discipline that keeps card debt low, while the Southwest is home to some of the nation's strongest regional economies.

But when you consider their earnings, denizens of big coastal cities -- not known for their frugality -- carry lower credit card debt burdens than others. Seven of the 10 cities with the shortest payback time were on the coasts; four of them in the East and three on the West Coast.

Then again, big coastal cities have other debts to contend with, notably their outsized housing costs. San Franciscans, for example, face a median home price of $748,300, more than four times that of San Antonio, according to the National Association of Realtors. Now that home prices are rising again, coastal homeowners may view their mortgage payments as a stockpile of value, not just a drain on income.