Sleep Cycle Calculator
Calculate optimal bedtime or wake-up time based on 90-minute sleep cycles for better rest.
How It Works
Sleep occurs in 90-minute cycles. Waking at the end of a cycle helps you feel refreshed. This tool calculates optimal times based on these cycles.
Sleep Cycle Facts
- One cycle: ~90 minutes
- Recommended: 5-6 cycles (7.5-9 hours)
- Minimum: 4 cycles (6 hours)
- Average time to fall asleep: ~14 minutes
FAQ
Q. Why 90-minute cycles?
A. Sleep alternates between light sleep, deep sleep, and REM sleep in approximately 90-minute cycles. Waking during light sleep between cycles feels most natural.
Q. How much sleep do I need?
A. Most adults need 7-9 hours (5-6 cycles). Individual needs vary, but consistently getting less than 6 hours increases health risks.