Having a husband creates an extra seven hours of housework each week for women, according to a new study.

Having a husband creates an extra seven hours of housework each week for women, according to a new study. For men, tying the knot saves an hour of weekly chores.

"It's a well-known pattern," said lead researcher Frank Stafford, an economist¹ at University of Michigan's Institute for Social Research. "Men tend to work more outside the home, while women take on more of the household labor²."

He points out individual differences among households exist. But in general, marriage means more housework for women and less for men. "And the situation gets worse for women when they have children," Stafford said.

Overall, times are changing in the American home. In 1976, women busied themselves with 26 weekly hours of sweeping-and-dusting work, compared with 17 hours in 2005. Men are pitching in more, more than doubling their housework hours from six in 1976 to 13 in 2005.

Stafford analyzed³ time-diaries and questionnaires from a nationally representative sample of men and women over a 10-year period from 1996 to 2005. The federally-funded study showed that, both the men and the women who got married did more housework than those who stayed single.

"Marriage is no longer a man's path to less housework," he said.

Single women in their 20s and 30s did the least housework, about 12 weekly hours, while married women in their 60s and 70s did the most - about 21 hours a week.

Men showed a somewhat different pattern, with older men picking up the broom more often than younger men. Single guys worked the hardest around the house, trumping⁴ all age groups of married men.

Having kids boosts house chores even further. With more than three kids, for instance, wives took on more of the extra work, clocking about 28 hours a week compared with husbands' 10 hours.