Sleep Calculator
Find the best time to go to bed or wake up so that you finish a full 90 minute sleep cycle.
I want to wake up at
- Go to bed at (6 cycles, 9 hours)
- 21:45
- Or at (5 cycles, 7.5 hours)
- 23:15
- Or at (4 cycles, 6 hours)
- 00:45
I am going to bed at
- Wake up at (4 cycles, 6 hours)
- 05:15
- Or at (5 cycles, 7.5 hours)
- 06:45
- Or at (6 cycles, 9 hours)
- 08:15
What is Sleep Calculator?
Sleep comes in cycles of about 90 minutes. Waking up at the end of a cycle, rather than in the middle of one, often feels easier.
What this tool does
Counts back from your wake-up time, or forward from your bedtime, in 90 minute steps, and allows 15 minutes to fall asleep. It shows the times for 4, 5 and 6 cycles.
How to use it
- Enter the time you want to wake up, or the time you go to bed.
- Read the suggested times.
- Pick the one that gives you the sleep you need.
Did you know?
- Most adults need seven to nine hours of sleep.
- Cycle length varies between people and through the night, so this is a guide, not a rule.