Sleep Calculator

Wake up rested with 90-minute sleep cycles.

You should go to bed at:
2:16 AM
4.5h · 3 cycles
Short rest
12:46 AM
6h · 4 cycles
Good
11:16 PM
7.5h · 5 cycles
Great
9:46 PM
9h · 6 cycles
Optimal
8:16 PM
10.5h · 7 cycles
Optimal
6:46 PM
12h · 8 cycles
Optimal
Tonight's recommendation
Go to bed at 9:46 PM for 9h of sleep (6 cycles).
90-min cycles
Each sleep cycle takes about 90 minutes.
14-min buffer
Average time to fall asleep, included automatically.
Wake light
Waking between cycles helps you feel rested.
Adults need 7–9 hours
Teens need 8–10 hours
Children need 9–12 hours
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