Plan sleep time from your own target
The calculator uses the hours of sleep you choose plus the time you allow to fall asleep. It returns a clock time and shows if that falls on the previous or next day.
This is a schedule calculation. It does not measure your sleep stages or predict the end of a sleep cycle. Your selected duration is an input, not a personal medical recommendation.
How to use this tool
- Choose to calculate bedtime or wake time.
- Enter the clock time, sleep hours and minutes to fall asleep.
- Read the resulting time and its day offset.
Example
To wake at 07:00 after 8 hours of sleep with 15 minutes to fall asleep, plan to go to bed at 22:45 on the previous day.
Common questions
Does it find the best moment in a sleep cycle?
No. It works with the duration you enter. Actual sleep stages cannot be identified from a clock time alone.