The cost of living in San Antonio is hampering residents' ability to save money — so much so that it takes years to build an ample emergency fund, according to a new study.

Financial site Bankrate.com crunched the numbers on how much Americans in the 50 largest metros need in their emergency funds — and how long it will take to save up. San Antonio-New Braunfels ranks No. 30 out of 50, making it one of the worst metros for savers.

In the San Antonio-New Braunfels area, residents need $20,151 in the bank to cover six months of expenses. But those earning the median income can only save $10,664 annually after covering housing costs and other necessities, according to Bankrate.com's analysis. It would take San Antonio-area residents earning the median income 22.7 months — almost two years — to save the necessary funds.

For its calculation, Bankrate started with the metro area's 2017 household median income provided by U.S. Census Bureau data. The study then subtracted the mortgage payments and property taxes on a median-priced home; estimated state and federal income taxes; and percentages spent on other essentials, like groceries, transportation, health costs, and utilities. Bankrate assumed the remaining funds would be put into savings.

"People living in areas with high housing costs could forgo all nonessential expenses for three years, religiously saving their extra dollars month after month, and still not accumulate enough cash for their recommended emergency fund," the study says.

This is the case in Austin-Round Rock, which is the worst spot for savers in Texas, at No. 38. Median income earners there need $26,712 to cover six months of expenses but can only save $7,770 a year. That means it takes Austinites 41.3 months, or more than three years, to save up a full fund.

How much someone needs to save and how long it takes varies greatly by location.

In Houston, No. 32, residents need $22,449 in their emergency funds, but median income earners can only set aside $11,039 a year. It would take Houston-area residents earning the median income 24.4 months to build up full emergency funds.

Then there's the Dallas-Fort Worth-Arlington area, which ranks No. 36. In the Metroplex, residents need $23,484 to cover six months of expenses. But those earning the median income can only save $9,704 in a year. If DFW residents pinched every penny they could, it would take 29 months to save a full fund.

Folks don't live like that, though, the study acknowledges. "Most of us don’t shove every extra dollar into the piggy bank, because we make 'nonessential' purchases for haircuts, toothbrushes, and other goods and services," the study says.

The best place to save money is Memphis, Tennessee, where the median income earner can set aside up to $15,761 a year, more than the $15,208 needed for a six-month emergency fund. California is home to the four worst metros for savers — it's "nearly impossible" to build savings in San Diego (No. 47), Los Angeles (No. 48), San Francisco (No. 49), and San Jose (No. 50).