Sleep hygiene
Sleep Cycle Planner
Sleep cycles last about 90 minutes. Waking at the end of a cycle can help you feel refreshed. Use this calculator to plan bedtimes or wake-up times aligned with full cycles.
Recommended options
4 cycles
Bedtime: 12:45 a.m.
Wake: 7:00 a.m.
Total sleep opportunity: 6.25 hours
5 cycles
Bedtime: 11:15 p.m.
Wake: 7:00 a.m.
Total sleep opportunity: 7.75 hours
6 cycles
Bedtime: 9:45 p.m.
Wake: 7:00 a.m.
Total sleep opportunity: 9.25 hours
How to Use This Calculator
Choose your mode
Start with either the time you must wake up or the bedtime you prefer.
Provide your sleep latency
Include the typical minutes it takes you to fall asleep so the schedule reflects total sleep opportunity.
Pick a cycle count
Most adults feel best with 5–6 cycles (7.5–9 hours). Short naps target 1–2 cycles to reduce grogginess.
Formula
Total sleep opportunity = (Number of cycles × 90 minutes) + Sleep latency
Bedtime = Wake time − Total sleep opportunity (wake-mode)
Wake time = Bedtime + Total sleep opportunity (bed-mode)
Adjust for personal cycle lengths (80–110 min) if you have sleep tracker data.
Full Description
Sleep architecture alternates between light sleep (N1/N2), deep sleep (N3), and REM. Waking during light sleep can reduce grogginess. Matching your schedule to complete cycles supports alert mornings and healthy circadian rhythms.
Factors such as age, stress, caffeine, and sleep disorders affect cycle length. If you frequently feel unrefreshed despite ample sleep, discuss symptoms with a healthcare provider or sleep specialist.
Frequently Asked Questions
Is 90 minutes exact for everyone?
No. Cycle length varies (80–110 min). Use 90 minutes as a starting point and adjust based on how you feel upon waking.
How many cycles should I aim for?
Most adults benefit from 5–6 cycles (7.5–9 hours). Athletes or those recovering from illness may need more.
Can I use this for naps?
Yes. For short naps, select 1 cycle (~90 min) or a 20–30-minute nap to stay in lighter sleep stages.
What if I have insomnia?
Structured sleep schedules help, but chronic insomnia requires medical evaluation and possibly CBT-I therapy.