Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
Sleep
REM Sleep Cycle Calculator
Find the ideal bedtime to wake up refreshed by aligning your alarm with the end of a complete 90-minute sleep cycle. Use it any night you want to avoid that groggy, mid-cycle wake-up feeling.
Fill in the required fields to see your result.
Sleep
Sleep Cycle Calculator
Find your ideal bedtime by working backward from your wake-up time in complete 90-minute sleep cycles. Waking at the end of a cycle (rather than mid-cycle) leaves you feeling more refreshed than the same total hours timed less carefully.
Fill in the required fields to see your result.
Key differences
| REM Sleep Cycle Calculator | Sleep Cycle Calculator | |
|---|---|---|
| Category | Sleep | Sleep |
| Inputs required | 3 | 2 |
| Result | Total Sleep Duration (minutes) | Optimal Bedtime (hours) |
| What it does | Find the ideal bedtime to wake up refreshed by aligning your alarm with the end of a complete 90-minute sleep cycle. Use it any night you want to avoid that groggy, mid-cycle wake-up feeling. | Find your ideal bedtime by working backward from your wake-up time in complete 90-minute sleep cycles. Waking at the end of a cycle (rather than mid-cycle) leaves you feeling more refreshed than the same total hours timed less carefully. |