Sleep
Tracker
Log your bedtime and wake time to see exactly how much sleep you're getting. Track weekly averages and sleep debt at a glance.
Log Sleep
Sleep This Week
Sleep Log
| Date | Bedtime | Wake | Hours |
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About this calculator
Sleep occurs in repeating 90-minute cycles, each moving through stages of light sleep, deep (slow-wave) sleep, and REM. Most adults need 7–9 hours per night, which corresponds to 4–6 complete cycles. This calculator suggests bedtimes or wake times that align with the end of a full cycle, when sleep is naturally lightest.
Consistently sleeping less than your body needs creates cumulative sleep debt, which impairs cognitive function, mood, and physical recovery. Waking mid-cycle — particularly during deep sleep — is why alarms can leave you feeling groggy even after a long night. Aiming to wake at the end of a cycle, rather than at a fixed duration, can help you feel more refreshed.