Sleep Calculator
Plan sleep cycles and recommended bedtimes around a target wake-up time
About Sleep Calculator
Sleep Calculator works backward from a target wake-up time or calculates a sleep schedule forward from the current time, offering six practical options centered on complete sleep cycles. The tool uses 90-minute intervals as a planning estimate and adds 15 minutes before the first cycle begins, making the results better suited to everyday routines. Users can prioritize recommendations for five or six complete cycles or choose an option suitable for a later bedtime; the results are for time planning, not medical measurement.
Best for
Best use cases
When the morning time is fixed but evening plans are uncertain
When planning tonight's sleep
When making a weekly sleep plan
Features
Work Backward from Target Wake-up Time
Enter the required wake-up time and calculate when to fall asleep based on complete sleep cycles.
Plan Forward from the Current Time
Plan a sleep schedule forward from the current time, suitable for checking tonight's options on the spot.
Six Cycle Options
Provides six practical options covering five or six complete cycles and recommendations for later bedtimes.
Sleep Onset Buffer
Adds 15 minutes before the first sleep cycle begins as a planning estimate that better reflects everyday routines.
Pros
- Provides six practical options centered on complete sleep cycles
- Works backward from a target wake-up time to plan when to fall asleep
- Includes 15 minutes before the first sleep cycle
Cons
- 90-minute intervals are planning estimates, not medical measurements
- Individual sleep needs vary
Pricing Plans
Free
- Online sleep-cycle planning
* Pricing information is for reference only. Please refer to the latest announcement on Sleep Calculator's official website.