Sleep cycles
Through the night you move through light, deep and REM sleep in cycles that average about 90 minutes. A typical night has four to six.
Sleep
calculator.
Pick when you want to wake up, or when you’re going to bed, and get times that fit whole sleep cycles.
Your times
A gentle guess
How the times
are worked out.
Falling asleep
We add the minutes it usually takes you to fall asleep (15 by default). Change it if you take longer.
Why whole cycles
Waking at the end of a cycle, in lighter sleep, may feel less groggy than waking from deep sleep. Cycles vary, so it’s a rough guide.
How much sleep
Sleep experts recommend that adults sleep 7 or more hours a night on a regular basis. Five or six cycles gets you there.
Sources: AASM & SRS consensus statement (2015) · Sleep Foundation: stages of sleep
Questions,
answered.
How many hours of sleep do adults need?
The American Academy of Sleep Medicine and Sleep Research Society recommend 7 or more hours a night, on a regular basis, for adults.
Is a sleep cycle always 90 minutes?
No. It’s an average. The first cycle is often shorter and later ones longer, and it changes with age, alcohol and how much sleep you’ve had recently.
Does waking between cycles really help?
Waking from lighter sleep can feel easier, but cycles are hard to time exactly. A regular schedule and enough total sleep matter more.
Should I see a doctor?
If you often struggle to fall or stay asleep, snore loudly, or feel very sleepy in the day despite enough time in bed, it’s worth talking to a doctor.
Rest is
on its way.
Rest is the gentle sleep app we’re building: read your nights from Apple Health or just your phone. Join the waitlist.