How To Calculate Hours Of Sleep: Time In Bed vs Time Asleep
Quick Answer: Subtract your wake time from your bedtime to get time in bed, then subtract the time it took …
Sleep Blog
The Sleep Calculators Online blog covers sleep science, sleep health and practical ways to sleep better. Articles explain how sleep stages and REM sleep work, why trouble falling asleep and waking at night happen, how your body clock shapes when you feel sleepy, and what sleep disorders such as sleep apnea, narcolepsy and restless legs look like.
Updated articles link to the research and health sources behind them, and many pair with a free tool such as the bedtime calculator, the sleep cycle calculator or the sleep debt calculator.
Looking for something specific? Browse sleep guides by topic, all sleep calculators or our pillow reviews. The newest articles are below.
Sleep Apnea Screening: Questionnaires To Home Tests
Sleep apnea screening uses questions and simple measures to flag who may need a proper test, and only a sleep …
Average Hours Of Sleep: How Much Do People Actually Sleep?
The average hours of sleep depends on how you ask. In a large CDC survey, about 35 percent of US …
Minimum Sleep Needed: How Little Is Too Little?
Quick Answer: For most adults the practical minimum is about 7 hours a night. Two major sleep societies say adults …
Oversleeping: What The Research Shows About Long Sleep
Quick Answer: Sleeping much more than 9 hours is linked to higher risk of death and disease in large studies. …
Why Do We Dream? Main Theories And The Evidence
Quick Answer: Scientists do not know for sure why we dream. NINDS says everyone dreams, about two hours a night, …
Does Lack Of Sleep Cause Weight Gain? What Trials Show
Quick Answer: Short sleep is linked to weight gain, and some trials show why: people eat more when they sleep …
Is 7.5 Hours Of Sleep Enough? What The Research Says
Quick Answer: For most adults, yes. A meta-analysis of prospective studies found the lowest risk of death and heart problems …
Sleep Restriction Therapy: What The Research Shows
Quick Answer: Sleep restriction therapy limits your time in bed to roughly the hours you actually sleep, then widens it …
Does The 90-Minute Sleep Cycle Rule Work? What Research Says
Quick Answer: Not exactly. Sleep cycles are not a fixed 90 minutes. An NIH source puts the first cycle at …