Explore several possible bedtimes from a desired wake time, or wake times from a planned bedtime. Select an assumed sleep-cycle length and an estimated time to fall asleep; the calculator then shows suggestions for several cycle counts. Sleep cycles are not identical for everyone or every night, so these are scheduling prompts, not guaranteed ideal times. Healthy sleep duration and consistency matter more than matching a cycle estimate. Seek medical advice for persistent sleep problems.
Choose whether you are starting from a bedtime or desired wake time.
Enter the clock time, assumed cycle duration and time to fall asleep.
Compare several suggested times and prioritize a consistent, adequate sleep schedule.
Time suggestion: Reference time ± (cycle count × assumed cycle minutes) plus sleep latency
Are 90-minute cycles guaranteed?
No. Cycle duration varies between people and through the night. The selected length is only a planning assumption.
Does the calculator diagnose sleep problems?
No. It is an informational time-planning tool. Ask a qualified clinician about ongoing sleep difficulties or health concerns.