Sleep Calculator

Find estimated bedtimes or wake-up times using sleep cycles.

Plan around 90-minute sleep-cycle estimates and a 15-minute fall-asleep allowance.

Your inputs stay on your device

Estimate your sleep schedule

live result

CalculateDesired wake-up time

Estimated bedtime (4 cycles)

00:45

same day

Estimated bedtime (5 cycles)

23:15

previous day

Estimated bedtime (6 cycles)

21:45

previous day

Sleep-cycle times are estimates based on 90-minute cycles and 15 minutes to fall asleep. They are not medical advice.

Context & Reference

Calculators are most useful when their assumptions are clear. Review these details to better understand the logic behind the results.

The calculator estimates sleep-cycle timing using 90-minute cycles and a short time to fall asleep.

Choose bedtime or wake-up mode, enter the known time, and compare suggested cycle-aligned times.

Each suggestion represents a cycle-count estimate, not a guarantee of sleep quality or an exact biological cycle.

Choosing a 07:00 wake-up time can show several suggested bedtimes with different cycle counts.

Sleep cycles vary between people. Results are estimates and are not medical advice or a substitute for professional care.

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