Free browser tool
Sleep Cycle Calculator
Pick the time you need to wake up to see bedtimes that end on a whole sleep cycle, or pick a bedtime to see good times to wake up. It counts in 90-minute cycles and adds the time it usually takes you to fall asleep.
Built with love by Shushant Lakhyani. Building bestproductivityresources.com
Go to bed at one of these times:
- 6 cycles · 9 h sleep
- 9:45 PM
- 5 cycles · 7.5 h sleep
- 11:15 PM
- 4 cycles · 6 h sleep
- 12:45 AM
- 3 cycles · 4.5 h sleep
- 2:15 AM
How it works: one sleep cycle is taken as 90 minutes, a common average. Real cycles vary from person to person and night to night (often between about 80 and 120 minutes), so treat these times as a rough guide, not a precise schedule. Bedtimes = wake-up time minus whole cycles minus the minutes you take to fall asleep. Health bodies such as the CDC and the American Academy of Sleep Medicine suggest most adults aim for 7 or more hours a night, so the 5 and 6 cycle options are usually the better picks. This is general information, not medical advice; if you have ongoing trouble sleeping or feel very tired during the day, talk to a doctor. Everything is worked out on your device.
Built with love by Shushant Lakhyani. Building bestproductivityresources.com
Private by design. This tool runs entirely in your browser. Nothing you enter or select is uploaded, saved, logged or shared, no AI service is used, and closing the tab clears everything.
Disclaimer. This free tool is provided "as is", without warranties of any kind, for general information and convenience. Results are general estimates for information only and are not medical advice, diagnosis or treatment. They may not suit your age, health or circumstances; speak to a qualified health professional before acting on them. You use it at your own risk. See the Disclaimer, Terms of Use and Privacy Policy.
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