Sleep in rhythm, wake up right
Sleep isn't a straight line — it's a series of dives to the depths and returns to the surface, roughly every 90 minutes. Pick a time, and we'll work out the rest.
Choose when you need to be alert — we'll count back in 90-minute cycles.
Or pick a common time
Why 90 minutes?
Each night, sleep repeats in loops of about 90 minutes, moving through 4 stages before starting over.
Drifting off
Drowsy and easily woken — the body is just starting to let go.
Light sleep
Heart rate and breathing begin to slow down.
Deep sleep
The body is nearly still — this is when physical recovery peaks.
REM sleep
The brain becomes active again to process memories, eyes moving rapidly.
Why timing your wake-up matters
If your alarm goes off in the middle of deep sleep, your brain gets jolted awake, leaving you groggy for hours — known as sleep inertia. Waking at the end of a cycle, during a lighter stage, leaves you far more alert.