Tool
Sleep calculator
Pick the time you need to wake up, or the time you're going to bed, and we'll suggest times that line up with the natural rhythm of sleep.
Your times stay on your device. We don't save or send anything you enter here.
How it works
During the night, sleep moves through repeating cycles of lighter, deeper and dreaming (REM) sleep. The first dreaming stage usually starts about 90 minutes after you fall asleep. This calculator uses 90-minute cycles and allows 15 minutes to fall asleep. It's a rough guide: everyone's cycles vary a little from night to night.
How much sleep adults need
Adults aged 18 to 60 should get at least 7 hours of sleep a night. Regularly sleeping less than 7 hours is linked to a higher risk of obesity, diabetes, high blood pressure, heart disease and stroke. More than a third of American adults don't regularly get enough.
If you often struggle to sleep or feel tired during the day, talk to a health professional.