This sleep calculator tells you when to go to bed so you wake up at the end of a sleep cycle. Pick your wake up time, add your age and weight, and see your best bedtimes, how much sleep you need, the calories you burn asleep and when to have your last coffee. Free, no signup.
Sleep Calculator
Wake up rested.
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See What’s Inside →Illustrative image. Individual results may vary.
Common questions
How many hours of sleep do I need?
Most adults need 7 to 9 hours a night, and people 65 and older do well on 7 to 8. It is a range because needs vary from person to person.
How does the sleep calculator pick my bedtime?
It counts back from your wake up time in 90 minute sleep cycles, plus about 15 minutes to fall asleep. Waking at the end of a cycle usually feels easier than waking in the middle of one.
Do I burn calories while I sleep?
Yes, your body keeps working all night. The calculator estimates about 0.95 calories per kilogram of body weight for each hour of sleep, so a 165 lb (75 kg) person sleeping 7.5 hours burns roughly 530 kcal. It is an estimate.
Why does the calculator show a last coffee time?
Caffeine stays in your body for hours, so a late coffee can cut into your sleep. The calculator suggests your last coffee 8 hours before bed. If you are sensitive to caffeine, go earlier.
Can better sleep help with weight loss?
For many people short sleep makes hunger louder and cravings stronger, so a full night makes the rest of your plan easier to keep. Sleep alone does not lose weight, but it helps everything else.
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Bye Weight is a weight loss community. No gym, no strict diet, no guilt. Just short lessons and simple walks.
See What’s Inside →Illustrative image. Individual results may vary.