Sleep Cycle Calculator

Find bedtimes or wake times that end at a full 90 minute sleep cycle, with four to six cycles.

Sleep cycle planner

I want to plan

Time (24 hour, hh:mm)

Minutes to fall asleep

Cycles to include

Best match: —

Time in bed: —

Cycles planned: —

Every option lines up with the end of a 90 minute cycle. Estimates for general information, not medical advice.

Common questions about the free online sleep cycle calculator.

It counts in 90 minute cycles of light, deep and REM sleep, then works back from your wake time or forward from your bedtime.

A full adult sleep cycle lasts about 90 minutes, so waking at the end of one usually feels easier than waking mid cycle.

Plan four to five cycles, about six to seven and a half hours of sleep, and use six cycles when you can sleep longer.

It adds the minutes you normally need to drop off, so the bedtime shown is when you should get into bed, not when you fall asleep.

Choose the bedtime mode, enter your wake time, and the list shows every bedtime that ends a full cycle.

Choose the wake time mode, enter your bedtime, and the list shows wake times that finish a complete cycle.

No, it plans night sleep only. A nap is usually one short cycle of about 20 to 90 minutes.

Yes. They are an estimate for general information and not medical advice, and individual cycle lengths do vary.

Last updated: October 10, 2026