Sleep Calculator
Optimize your sleep by waking between sleep cycles
Range: 1 - 12
Range: 0 - 59
To wake up at 7:00 AM, go to bed at:
9:45 PM
6 cycles
9.3 hours
Recommended
11:15 PM
5 cycles
7.8 hours
Recommended
12:45 AM
4 cycles
6.3 hours
2:15 AM
3 cycles
4.8 hours
Sleep Cycle Duration
90 minutes
Average complete cycle
Fall Asleep Time
15 minutes
Average time to fall asleep
Sleep Cycle Stages
N1
N2
N3
N2
REM
N1: Light sleep | N2: True sleep | N3: Deep sleep | REM: Dream sleep
Tips for Better Sleep
- Wake between sleep cycles to feel more refreshed
- Keep a consistent sleep schedule, even on weekends
- Avoid screens 1 hour before bed (blue light disrupts melatonin)
- Keep your bedroom cool (65-68°F / 18-20°C)
- Avoid caffeine 6+ hours before bed
- Adults need 7-9 hours of sleep per night
How It Works
Sleep occurs in cycles of approximately 90 minutes each. Waking up at the end of a cycle (during light sleep) rather than in the middle (during deep sleep) helps you feel more rested. This calculator accounts for an average of 15 minutes to fall asleep and recommends times that align with completed sleep cycles.
Related Tools