Estimate a bedtime from a wake clock, minutes to fall asleep, and 90-minute sleep cycles.
| Bed hour | – |
| Bed minute | – |
| Hours in bed | – |
Use this calculator for time in bed ≈ fall-asleep minutes + cycles × 90, then subtract that span from the wake clock. Five cycles is about 7.5 hours plus the time to fall asleep. Circadian and REM clones that only shift this arithmetic are merged here. This is not a sleep-lab report.
Wake hour: Hour you want to get up, 0–23.
Wake minute: Minutes past that hour, 0–59.
Fall-asleep (min): Minutes to fall asleep. 14 is a common sketch.
Cycles: How many 90-minute blocks.
Bed hour: Suggested hour to go to bed.
Bed minute: Suggested minute to go to bed.
Hours in bed: Fall-asleep time plus cycle time, in hours.
Related calculators