It’s a generalization, of course. Individuals vary greatly so this fact won’t apply to everyone. But sleep experts say that on average, women need about 20 minutes’ more sleep than men do—some even more. The difference is explained by gender differences in the brain, life issues, and physicality.
The brain’s a battery
Your brain must be “recharged” during sleep, because all the thinking you do all day has to be processed. Sleep experts say women use more of their brains during the day than men do, because they tend to multi-task.
“'A man who has a complex job that involves a lot of decision-making and lateral thinking may also need more sleep than the average male, though probably still not as much as a woman,” said professor Jim Horne in a Daily Mail interview. Horne directs the Sleep Research Center at Loughborough University in the U.K. and is the author of Sleepfaring: A Journey Through The Science Of Sleep. “This is because women's brains are wired differently from men's and are more complex.”
A man at age 70 has the average brain age capacity of a woman at age 75. The difference may be partially explained by the fact that the average woman tends to sleep a little longer than the average man, so her brain has more time for nightly repair.
On the other hand, many women are struggling with larger sleep deficits in the first place. The UCLA Sleep Disorders Center reports that women are twice as likely as men to have trouble falling and staying asleep. A University of Surrey study showed that 18 percent of women report a bad night’s sleep about five days per week, compared to 8 percent of men.
Women sleep more lightly
For several reasons, according to the American Academy of Sleep Medicine, women’s sleep tends to be lighter and more broken than men’s.
Menstruation causes cramping pain and alters hormone levels in ways that disturb sleep. Mothers are more highly tuned, biologically, to distress sounds from a child. Even just a spoken “Mommy” brings many women to full wakefulness. Not all men can sleep through a child’s voice or crying, but many do. That’s significant because although the stages of sleep occur in cycles all night—the cycles aren’t all the same. More deep-sleep stages occur during the earlier part of the night, when babies and children are most restless.
Restless sleep isn't over when children leave the nest. Menopause, with its hormonal changes and hot flashes, breaks up women’s deepest sleep, often for years as it comes on. And for reasons not fully understood, women experience pain more intensely than men do, which may also affect the quality of their sleep.
Once awakened, women have a harder time getting back to sleep. This may be because they are more worried. According to a survey by Money magazine, two-thirds of women say they're worried about their financial outlook, compared with 54 percent of men. On average, most women carry more caregiving responsibilities and a heavier economic burden. According to the American Psychological Association’s 2014 report on stress in America, on average, women report a higher level of stress than men. Women are more likely than men to report money and family responsibilities as significant sources of stress.
Far more women than men (51 percent versus 32 percent) report lying awake at night due to stress. These factors may explain why, in general, more men are able to “turn it all off” and go back to sleep.