Sleep Calculator
Wake up refreshed by timing sleep around 90-minute cycles. Tell us when you want to wake up, or when you are heading to bed, and we will suggest the moments that land between cycles, not in the middle of one.
To wake up at 7:00 AM, head to bed at one of these times. Each option is a whole number of sleep cycles, the highlighted ones are the sweet spot.
If you fall asleep around now, set an alarm for one of these wake-up times. The highlighted options give you the most restorative sleep.
Why 90 minutes?
Sleep moves through repeating cycles of roughly 90 minutes, each running from light sleep down into deep sleep and REM, then back toward light sleep. Waking at the end of a cycle, when you're already near the surface, tends to feel far easier than being jolted awake from deep sleep, even if you've slept slightly less overall.
Most adults do best on 5-6 cycles (about 7.5-9 hours). We also add ~15 minutes to fall asleep, since you don't drift off the instant your head hits the pillow. These are friendly estimates, cycle length varies from person to person, so treat the highlighted picks as a starting point and adjust to what leaves you feeling rested.