It's not as often as you may think. 

By Brigitt Earley
Updated November 18, 2015
Credit: Shana Novak/Getty Images

You've probably heard it from self-help books and friends over and over: frequent sex equals greater relationship satisfaction. But here's some good news for those who'd rather get some shut-eye: once a week might be enough to keep a couple happy, according to a new study published by the Society for Personality and Social Psychology.

"Although more frequent sex is associated with greater happiness, this link was no longer significant at a frequency of more than once a week," lead researcher Amy Muise said in a statement. "Our findings suggest that it's important to maintain an intimate connection with your partner, but you don't need to have sex every day as long as you're maintaining that connection."

Based on surveys of more than 30,000 Americans collected over four decades, there appears to be a threshold: Couples who have sex more than once a week are no happier than those who have sex weekly, but couples who have sex less than once a week report being less satisfied.

And, despite the stereotype that sex is more of a priority to men, the research seemed to transcend gender, age, and relationship length: "Our findings were consistent for men and women, younger and older people, and couples who had been married for a few years or decades," Muise said.

Although doing the deed once a week seems to be optimal, researchers explain that couples shouldn't necessarily engage in more—or less—sex just to reach this number. Because the findings do not clarify whether having more sex makes couples happier or if happier couples tend to have more sex, "it's important to maintain an intimate connection with your partner without putting too much pressure on engaging in sex as frequently as possible," Muise said.