Sleep Calculator

Find ideal bedtimes based on 90-minute sleep cycles.

09:15 PM

9.0 hours

6 cycles

10:45 PM

7.5 hours

5 cycles

12:15 AM

6.0 hours

4 cycles

01:45 AM

4.5 hours

3 cycles

💡 Includes 15 min to fall asleep. 5-6 cycles = optimal rest.

About Sleep Calculator

This is a free, fast, and fully client-side sleep calculator tool. All processing is done locally within your browser to ensure maximum privacy and security. No data is sent to our servers. Bookmark this page for quick access to ad-free, high-performance SEO and developer utilities.