FAQ
Use this FAQ to understand what Best Time For Bed can and cannot estimate, why sleep cycles vary, and how to use the calculators responsibly.
How accurate is a sleep calculator?
It is an estimate. The calculator can perform time arithmetic based on a simplified sleep-cycle model, but it cannot measure your actual sleep stages. Real sleep cycles vary throughout the night.
How much sleep should adults get?
CDC guidance says adults ages 18–60 should generally get 7 or more hours per night; adults 61–64 are listed at 7–9 hours and adults 65+ at 7–8 hours.
Is 90 minutes one exact sleep cycle?
No. NHLBI describes cycles restarting approximately every 80–100 minutes. The 90-minute number is a simplified planning convention.
Can the calculator diagnose a sleep disorder?
No. It is not a medical device and cannot diagnose insomnia, sleep apnea, narcolepsy, or other conditions.
What is the best bedtime?
The best bedtime is one that lets you get enough sleep before your required wake time and can be maintained consistently.
Frequently Asked Questions
How accurate is a sleep calculator?
It is an estimate and cannot measure your real sleep stages.
How much sleep should adults get?
CDC guidance generally recommends 7 or more hours for adults 18–60.
Is a 90-minute sleep cycle exact?
No. Sleep cycles vary, and NHLBI describes an approximate 80–100 minute cycle.
Can a sleep calculator diagnose insomnia?
No. Persistent sleep problems should be evaluated by a healthcare professional.