Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
Sleep
Optimal Bedtime Calculator
Work out exactly what time to go to bed so you wake up feeling rested and aligned with full sleep cycles. Perfect for anyone who wants to stop waking up groggy.
Fill in the required fields to see your result.
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.
Key differences
| Optimal Bedtime Calculator | REM Sleep Cycle Calculator | |
|---|---|---|
| Category | Sleep | Sleep |
| Inputs required | 4 | 3 |
| Result | Optimal Bedtime (hour) | Total Sleep Duration (minutes) |
| What it does | Work out exactly what time to go to bed so you wake up feeling rested and aligned with full sleep cycles. Perfect for anyone who wants to stop waking up groggy. | 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. |