Sleep Calculator
Calculate optimal bedtimes and wake times based on 90-minute sleep cycles. Wake up feeling refreshed by completing full cycles.
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About Sleep Cycles
Each cycle is ~90 minutes. Adults need 5-6 cycles (7.5-9 hours) for optimal rest.
Recommended Bedtimes
for 6 cycles (9 hours) of optimal sleep
Bedtime Options
Sleep Tips
- • Keep a consistent sleep schedule, even on weekends
- • Avoid caffeine 6+ hours before bedtime
- • Create a dark, cool, quiet sleeping environment
- • Avoid screens 1 hour before bed
Documentation
Sleep Cycles
Sleep occurs in cycles of approximately 90 minutes each. Each cycle includes light sleep, deep sleep, and REM (dreaming) stages.
Why Cycles Matter
"Waking up mid-cycle causes grogginess. Waking at the end of a cycle helps you feel refreshed."
Recommended Sleep
Adults (18-64): 7-9 hours
Older Adults (65+): 7-8 hours
Teens (14-17): 8-10 hours
Add ~15 minutes for time to fall asleep