# Sleep Cycle Calculator

> Find the best times to sleep or wake based on 90-minute sleep cycles.

To find the best time to sleep or wake, enter your target time. Sleep runs in roughly 90-minute cycles, and waking at the end of a cycle rather than mid-cycle usually feels less groggy. An extra 15 minutes is added for the time it takes to fall asleep.

**URL:** https://convertto.tech/t/sleep-calculator
**Category:** Health & Fitness (https://convertto.tech/c/health-tools)
**Privacy:** Runs entirely in the browser; no upload
**Cost:** Free, no sign-up
**Last updated:** 2026-08-01

## Key facts

- **Privacy:** Runs entirely in your browser — nothing is uploaded
- **Cost:** Free, unlimited, no sign-up

## How to use

1. Enter or paste your time.
2. Choose the i want to.
3. The result appears immediately — copy or download it.

## FAQ

### Are sleep cycles really 90 minutes?

Ninety minutes is the population average, but individual cycles range from roughly 70 to 120 minutes and change through the night. Treat these times as a guide rather than a precise schedule.

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