Sleep Cycle Calculator

Find the best bedtime or wake time using 90-min sleep cycles.

Time:

How to use

Pick 'wake up' or 'go to bed', set a time, and get cycle-aligned options.

Why 90 minutes?

A full sleep cycle lasts ~90 min; waking between cycles feels better.

☕

Every tool runs 100% in your browser — no uploads, no signups. If a tool saved you time, consider supporting us with a small donation.