Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
Sleep
REM Sleep Calculator
Estimate how much of your nightly sleep is spent in REM based on total sleep time and age. REM sleep is critical for memory consolidation, emotional processing, and creative problem-solving, and is the first stage to be cut short by sleep restriction.
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 Calculator | Sleep Cycle Calculator | |
|---|---|---|
| Category | Sleep | Sleep |
| Inputs required | 2 | 2 |
| Result | Estimated REM Sleep (hours) | Optimal Bedtime (hours) |
| What it does | Estimate how much of your nightly sleep is spent in REM based on total sleep time and age. REM sleep is critical for memory consolidation, emotional processing, and creative problem-solving, and is the first stage to be cut short by sleep restriction. | 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. |