Instead of waiting till they tie the knot, more couples today are moving in together to cut costs. But does cohabitation really save money?

New research shows that living together can save a buck -- but there's a catch. While cohabiting couples save about 1.4 times more money than those who don't shack up, how much they put away depends on their careers and backgrounds.

College-educated unmarried couples who lived together saved far more money than those who only finished high school, according to the Pew Research Center.

This is could in part be explained by their income levels. College-educated couples who are unmarried but live together have an average household salary of $106,400 while married college grads share an average $101,160 combined salary.

In contrast, unmarried cohabiting couples who have only completed high school have a median income of $46,540 and married high school-educated couples have a combined salary of $56,800.

Pew researchers say children may factor in to the trend. College-educated couples were less likely to have kids before they tied the knot compared to those who didn't get their college degree. In addition, higher-educated couples are more likely to marry within three years of living together as well as "pool their resources" more efficiently, they said.

Cohabitation is more common among "less educated" couples, according to the Pew figures. Among women aged 19 to 44, 73 percent who only have a high school degree have lived with a mate compared to 52 percent of women with some college education and 47 percent who graduated from college.