Sleep Calculator
Plan bedtimes or wake-up times by full sleep cycles.
Inputs
Set your desired wake-up time.
Or set your bedtime.
Typical cycle ≈ 90 minutes.
Common default is about 15 minutes.
Try 4–6 cycles for most adults.
Auto avoids backfilling and feels “live”.
Results
Calculated bedtime
Calculated wake-up time
Total time in bed
Latency + (cycles × cycle length)
Tip: waking at the end of a cycle often feels easier than mid-cycle.
This calculator uses an approximate cycle model; real cycles can vary by person and night.

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