Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
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.
Sleep
Sleep Debt Calculator
Quantify how many hours of sleep you owe your body by comparing your ideal sleep need against actual sleep over a period of days. Accumulated sleep debt impairs cognition, mood, immune function, and metabolic health well before you "feel" tired.
Fill in the required fields to see your result.
Key differences
| Sleep Cycle Calculator | Sleep Debt Calculator | |
|---|---|---|
| Category | Sleep | Sleep |
| Inputs required | 2 | 3 |
| Result | Optimal Bedtime (hours) | Total Sleep Debt (hours) |
| What it does | 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. | Quantify how many hours of sleep you owe your body by comparing your ideal sleep need against actual sleep over a period of days. Accumulated sleep debt impairs cognition, mood, immune function, and metabolic health well before you "feel" tired. |