"ZIP code 20015 covers the D.C. neighborhood that straddles the Maryland border and is south of both Chevy Chase and Silver Spring," notes GOBankingRates, adding that, "over the years, the nation's capital has earned a reputation for its escalating cost of living." To calculate exactly how much you'd need to earn to live there comfortably, GOBankingRates used the 50-30-20 budget rule: 50 percent of your income would be used to cover necessities, 30 percent is discretionary income and 20 percent is allocated to savings. "Monthly costs were totaled and multiplied by 12 to get the annual dollar cost of necessities in each ZIP code," writes GOBankingRates. "This dollar amount for necessities was then doubled to find the actual annual income needed to live in the location."