Sleep cycle calculator
When should
you sleep
tonight?
Tell us when you wake up. We'll find the perfect time for you to drift off.
Best
Sleep tonight at
Tonight's tip
Also works
Option 2
Option 3
🔬
Why these times?
Sleep happens in 90-minute cycles. Waking up at the end of a cycle — not the middle — means you feel refreshed instead of groggy. These times are calculated to land you at the end of a complete cycle.
Quick reference — 7AM wake up
11:15 PM
6 cycles · 7.5h
12:45 AM
5 cycles · 6h
2:15 AM
4 cycles · 4.5h