Sleep Time Calculator.
Sleep Time Calculator answers two everyday questions: when to go to bed for a fixed alarm, and when to set the alarm if you're going to bed now.
Project overview
The short version
Sleep Time Calculator answers two everyday questions: when to go to bed for a fixed alarm, and when to set the alarm if you're going to bed now. It counts in 90-minute cycles and adds about 14 minutes for falling asleep. A nap tab suggests 10, 20, 30, 60 or 90 minutes, and sister pages cover sleep debt, jet lag and a cycle calculator where you set your own cycle length. Everything runs in the browser with no account. The site shows Google AdSense ads and uses Google Analytics, and it says no named clinical reviewer has checked its medical claims yet.
Project facts
Project details
- Category
- Other
- Type
- Not listed
- Platforms
- See Project Note
- Pricing
- See Project Note
- Availability
- Other
- Published
- Oct 24, 2026
Details come from the published Project Note and named sources. Check the project site for current terms. The Note may have more context when a fact isn't recorded here.
Before you visit
Good to know
Built for
- People with a fixed early alarm who want cycle-aligned bedtimes, and nappers deciding between a short nap and a full 90 minutes.
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