By age, adults 18 to 64 need 7 to 9 hours of sleep and adults 65 and over need 7 to 8 hours. By gender, the official recommendations are the same for men and women. Large reviews mostly find no meaningful sex difference in how much sleep people need, even though women and men do tend to sleep somewhat differently.
That's why the sleep needs by age calculator asks for your age and wake-up time but not your gender. Your age sets the range; your wake-up time turns it into a bedtime window.
Free toolSleep Needs by AgeRecommended hours for every age, from newborns to over-65s.Sleep calculator by age and gender: the numbers
For adults, the recommended range depends on age only. Here it is for men and women, with the bedtime window for a 7:00 AM alarm, allowing 15 minutes to fall asleep.
| Age | Men | Women | Bedtime window for a 7:00 AM wake-up |
|---|---|---|---|
| 18 to 25 | 7 to 9 h | 7 to 9 h | 9:45 PM to 11:45 PM |
| 26 to 64 | 7 to 9 h | 7 to 9 h | 9:45 PM to 11:45 PM |
| 65 and over | 7 to 8 h | 7 to 8 h | 10:45 PM to 11:45 PM |
These ranges come from National Sleep Foundation expert panels. In 2026, the foundation reviewed 133 meta-analyses published over the previous decade and re-certified the same ranges. Most of those meta-analyses reported no significant difference between men and women.
For children and teens, the ranges are wider and change every few years of age. Use the sleep needs by age tool, which covers newborns through teens.
How to calculate your bedtime by age
The formula is: earliest bedtime = wake-up time minus 15 minutes minus the top of your range; latest bedtime = wake-up time minus 15 minutes minus the bottom of your range.
Worked example for a 6:30 AM alarm:
- Adult 18 to 64 (7 to 9 h): 6:30 AM minus 15 min minus 9 h = 9:15 PM. 6:30 AM minus 15 min minus 7 h = 11:15 PM. Your bedtime window is 9:15 PM to 11:15 PM.
- Adult 65+ (7 to 8 h): 6:30 AM minus 15 min minus 8 h = 10:15 PM. The latest bedtime is still 11:15 PM. Your window is 10:15 PM to 11:15 PM.
If you take longer than 15 minutes to fall asleep, subtract your real number instead. The sleep calculator then fine-tunes the window to the end of a sleep cycle, and if you're over 65, how much sleep older adults need goes deeper on that age group.
Do women need more sleep than men?
The evidence doesn't show that women need more sleep than men. You may have seen a claim that women need about 20 minutes more. That figure isn't part of any official guideline, and the large 2026 review of meta-analyses found mostly nonsignificant sex differences in sleep duration.
What the research does show is that women and men sleep differently in practice:
- Women tend to sleep a little longer. In a wearables study of more than 11 million nights from about 69,650 adults in 47 countries, men slept less than women across the adult lifespan.
- Women wake up more during the night. The same study found nighttime awakenings were more common in women, with the biggest gap in early to middle adulthood, the years often associated with raising children.
- Women report more insomnia. A meta-analysis of about 1.27 million people found women had roughly 1.4 times the risk of insomnia compared with men, and the gap grew with age.
Put together: sleeping longer isn't the same as needing more. If your nights are more broken, you may spend more time in bed to get the same amount of actual sleep. That's a quality issue, not a different requirement.
Sleep calculator for women: what to adjust
Use the same 7-to-9-hour range, then adjust for how well you actually sleep. A few practical tweaks:
- Count real sleep, not time in bed. If you wake often, your time in bed may be 8 hours while your sleep is closer to 7. The sleep efficiency calculator shows the gap.
- Aim for the upper half of the range when nights are broken, such as during pregnancy, early parenting, or menopause-related night sweats.
- Add your real time to fall asleep. If it's usually 30 minutes, a 6:30 AM alarm with 8 hours of sleep means lights out at 10:00 PM, not 10:15.
- Watch for insomnia that lasts weeks. Trouble falling or staying asleep most nights for a month or more is worth raising with a doctor. It's common and treatable.
The same checks apply to men. Loud snoring with gasping or pauses in breathing, or heavy daytime sleepiness despite enough hours, are reasons to see a doctor regardless of gender.
Does sleep need change with age?
Sleep need changes only a little across adulthood, but sleep itself changes more. The recommended range narrows from 7 to 9 hours to 7 to 8 hours after 65. Meanwhile, sleep tends to get shorter, bedtimes and wake times drift earlier, and nighttime awakenings become more common with age, according to the wearables data.
So an older adult who wakes at 5:30 AM and can't get back to sleep isn't necessarily short on sleep. They may just need an earlier bedtime. Enter your age and wake-up time into the sleep needs by age calculator to see the window that fits, or compare bedtimes in a good bedtime for adults.