Sleep Calculator

Find recommended bedtimes or wake times based on 90-minute sleep cycles.

Wake-up time

Time to fall asleep (optional) min

Fill in the fields above and press Calculate or hit Enter ↵

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Sleep cycles and bedtime planning

Last updated: March 30, 2026

A sleep calculator uses 90-minute cycle planning to recommend better bedtimes for a target wake-up time. Waking between cycles can improve morning alertness compared with waking mid-cycle.

Because most people need a short time to fall asleep, the tool includes sleep latency adjustment. This makes bedtime suggestions more practical than generic fixed-time advice.

Queries like "best bedtime for 6am wake up" map directly to this calculator and provide immediate, actionable times.

Frequently asked questions

Why use 90-minute sleep cycles?

Most sleep cycles last around 90 minutes. Waking between cycles can reduce grogginess compared with waking mid-cycle.

How many cycles should I target?

Five to six full cycles is usually ideal for adults, depending on your schedule and sleep needs.

Does this include time to fall asleep?

Yes. You can set your estimated sleep latency, and the default is 15 minutes.