Sleep Calculator Guide
Complete guide to using our sleep calculators. Learn how to calculate your ideal bedtime, wake time, and sleep cycles for maximum rest.
Sleep Guides & Articles
Over 30 evidence-based guides on sleep science, circadian rhythms, and practical strategies for better rest. Each guide references peer-reviewed research from the National Sleep Foundation, AASM, and the NIH.
Where to Start
- New to sleep science? Start with Sleep Calculator Guide and How Much Sleep Do I Need?
- Want better sleep tonight? Read Sleep Hygiene Tips and Sleep Environment Tips
- Struggling with a specific issue? Check Caffeine and Sleep, Insomnia Guide, or Shift Work Sleep
- Want to use a calculator? Browse our 5 free sleep calculators
Getting Started
Essential reading for understanding how sleep works and how to use our tools effectively.
How Much Sleep Do I Need?
Find out exactly how much sleep you need based on your age, lifestyle, and activity level, with National Sleep Foundation guidelines.
Bedtime Calculator Guide
Find the ideal time to go to sleep based on your wake-up time, factoring in 90-minute sleep cycles and time to fall asleep.
Sleep Cycles Explained
The complete guide to sleep stages: light sleep, deep sleep, and REM. Understand what happens in each stage and why cycles matter.
Sleep Cycle Science
Deep dives into the biology of sleep cycles, individual sleep stages, and how to time your sleep for each stage.
The 90-Minute Sleep Cycle
The science behind the 90-minute sleep cycle, including how each cycle differs throughout the night and why timing matters.
Sleep Cycle Calculator Guide
How to use the sleep cycle calculator to analyze your nightly cycles and optimize time spent in deep and REM sleep.
REM Sleep Calculator
Everything about REM sleep: why you need it, how much you should get, and how to increase your dream sleep.
Deep Sleep Calculator
How much deep sleep do you need by age? Learn what deep sleep does for physical recovery, immunity, and growth hormone.
Light Sleep Explained
Understanding N1 and N2 sleep stages: what happens during light sleep, how much you need, and why it's not "wasted" sleep.
Circadian Rhythm Guide
How your 24-hour body clock controls sleep, alertness, and hormone production. Includes tips for resetting your rhythm.
Sleep Optimization
Practical strategies for improving your sleep quality, environment, and schedule based on peer-reviewed research.
Sleep Hygiene Tips
15 evidence-based sleep hygiene habits including screen rules, temperature, exercise timing, and pre-bed routines.
Sleep Quality Tips
12 proven strategies to improve sleep quality beyond just sleep duration, from cognitive techniques to environmental tweaks.
Sleep Environment Tips
How to create the perfect bedroom for sleep: temperature, lighting, noise, mattress selection, and air quality.
Optimal Sleep Duration
How to find your personal sleep sweet spot. Not everyone needs 8 hours — discover what works for your body.
Best Time to Wake Up
How to choose the ideal alarm time based on your bedtime and sleep cycle alignment to wake up feeling energized.
Sleep Schedule Calculator
Build and maintain the perfect sleep schedule. How consistency affects your circadian rhythm and overall sleep quality.
Sleep Duration by Age
Age-specific sleep recommendations from the National Sleep Foundation, with practical advice for every life stage.
Sleep Calculator by Age
Discover exactly how much sleep you need at every age, from newborns to seniors, with science-backed recommendations.
Sleep by Age Calculator Guide
A complete age-by-age sleep guide with recommended hours, sleep tips, and common challenges for each age group.
Napping Science
When, how long, and how to nap without disrupting your nighttime sleep.
Nap Calculator Guide
Find the optimal nap length for your goals: 20 minutes for alertness, 60 for memory, 90 for a full cycle.
Power Nap Guide
The science-backed guide to 10-20 minute power naps: timing, techniques, and how to avoid grogginess.
Sleep Debt & Deprivation
Understanding accumulated sleep loss, its health consequences, and evidence-based recovery strategies.
Sleep Debt Calculator Guide
How to calculate your sleep debt, understand the health risks of accumulated loss, and build a realistic recovery plan.
Effects of Sleep Deprivation
What happens to your brain and body when you don't get enough sleep: cognitive decline, immune damage, and chronic disease risk.
Sleep & Health
How sleep connects to mental health, weight management, caffeine, melatonin, and common sleep disorders.
Caffeine and Sleep
How caffeine disrupts sleep cycles, how long it stays in your system, and the best cutoff time to stop drinking coffee.
Melatonin and Sleep
How melatonin works, the right dosage (it's lower than you think), timing, side effects, and when supplements help.
Sleep and Weight Loss
How sleep affects metabolism, appetite hormones (leptin and ghrelin), and why poor sleep makes weight loss harder.
Sleep and Mental Health
The bidirectional relationship between sleep and mental health: depression, anxiety, and how improving sleep helps both.
Sleep Disorders Guide
Types, symptoms, and treatments for common sleep disorders including insomnia, sleep apnea, restless legs, and narcolepsy.
Insomnia Guide
Causes, symptoms, and evidence-based treatments for insomnia, including CBT-I, sleep restriction, and stimulus control.
Special Topics
Specialized sleep guidance for athletes, shift workers, and those interested in alternative sleep schedules or tracking technology.
Sleep for Athletes
How sleep impacts athletic performance, recovery, injury risk, and reaction time. Sport-specific recommendations included.
Shift Work and Sleep
Evidence-based strategies for night shift and rotating schedules: light exposure timing, anchor sleep, and melatonin use.
Polyphasic Sleep Guide
Everyman, Uberman, and other polyphasic schedules: the science, the risks, and who (if anyone) should try them.
Sleep Tracker Guide
How to choose and use a sleep tracker. Comparison of wearables, smart rings, and under-mattress sensors.
Ready to Optimize Your Sleep?
Pair these guides with our free calculators to find your ideal bedtime, wake time, and sleep schedule.
Frequently Asked Questions
Start with the Sleep Calculator Guide for an overview of all our tools, then read How Much Sleep Do I Need? to understand your personal sleep needs. From there, explore specific topics like sleep cycles, sleep hygiene, or circadian rhythms based on your interests.
Yes. Every guide references peer-reviewed studies and recommendations from the National Sleep Foundation, the American Academy of Sleep Medicine, the CDC, and the National Institutes of Health. We cite specific studies and link to PubMed sources where applicable.
No. The guides are standalone resources that explain sleep science, practical tips, and health connections. However, pairing the guides with our free sleep calculators gives you both the knowledge and the tools to optimize your sleep. For example, read the 90-Minute Sleep Cycle guide, then use the Bedtime Calculator to apply what you learned.
We review and update guides regularly as new research is published. Sleep science evolves, and we incorporate findings from the latest peer-reviewed studies. Each guide reflects current consensus from major sleep research organizations.