METHOD
Formula and method
Bedtime = wake time − desired sleep duration − entered settling time.
Bedtime planner from your wake time and sleep goal
Plan bedtime using your own desired sleep duration.
01
Your inputs
Starting values are an example. Replace them with your own.
Your inputs stay in your browser.
02
Your result
Enter your details and run the calculation.
About this result
This planner does not predict sleep stages or guarantee feeling rested. It does not assume that every sleep cycle lasts exactly 90 minutes.
Full disclaimerWhat time should I go to bed for eight hours of sleep?
The calculator subtracts your desired sleep duration and your estimated time to fall asleep from your wake time. To wake at 07:00 with 8 hours of sleep and 15 minutes to drop off, go to bed at 22:45. When the bedtime is later than the wake time, it refers to the previous day. The planner does not predict sleep stages, does not assume cycles of exactly 90 minutes and cannot promise you will feel rested.
TRACEABLE
Sources and validity
Basic arithmetic or geometry using the formula shown. Uses only your inputs.
How we maintain data