# Sleep cycle calculator

> Sleep Cycle Calculator is a free English-language tool for planning bedtime or wake-up time. Enter a clock time and your time to fall asleep, then compare 8-hour, 7.5-hour, and 9-hour sleep plans. Calculations run in your browser, with no account required.

Content reviewed: 2026-11-09.

## Public pages

- [Calculator and guide](https://sleepcyclecalculator.net/): Find bedtime or wake-up times with our free sleep cycle calculator. Compare 8, 7.5, and 9 hours of sleep, including time to fall asleep.
- [About](https://sleepcyclecalculator.net/about): A simple, free sleep calculator for planning bedtime and wake-up time. Learn how it works, what it includes, and what it cannot predict.
- [Privacy](https://sleepcyclecalculator.net/privacy): How Sleep Cycle Calculator handles local preferences, browser calculations, hosting requests, and optional future integrations.

## Full guide

- [Product facts, instructions, limitations, and FAQ](https://sleepcyclecalculator.net/llms-full.txt): Text from the public website.

## Discovery

- [Sitemap](https://sleepcyclecalculator.net/sitemap.xml)
- [Robots policy](https://sleepcyclecalculator.net/robots.txt)