Living alone may well be impossible for recent college graduates, at least in the nation's largest markets for apartment rentals.

According to a new study from Trulia, the median starting salary for college graduates aged 22 to 25 was hardly enough to afford apartment listings in the 25 largest U.S. rental markets. This means most recent college grads will have to live with at least one roommate to live in the country's biggest cities.

A website that helps prospective renters and homeowners find apartments and homes, Trulia used median figures for rent in each of the 25 cities with the most apartment listings and compared it to median starting salaries for recent college grads. They deemed listings affordable if the monthly payment was, at most, 31 percent of the person's monthly paycheck.

For example, the median rent in Portland Ore. is $1,215 per month and the median salary for recent college graduates is $18,560 per year, making 0.1 percent of the city's listings affordable. San Francisco came in as the city that required the highest annual income at $137,272, which is $96,028 higher than the median starting salary for recent college grads.

St. Louis, Mo. came in as the most affordable city for recent college grads, as 18.6 percent of listings could be managed on one income. Rounding out the top five in that category was Dallas, Houston, Atlanta and Phoenix.

"Many of the metros that pay the highest salaries also come with hefty rental price tags," the report read. "The lesson here for recent grads is that although it may be tempting to seek out metros with the highest wages, doing so may not necessarily lead to a better quality of life because these metros also have high rents."