Not a medical device
Results are arithmetic estimates from times and preferences you enter. The site does not measure brain activity, breathing, movement, blood oxygen, actual sleep duration, NREM stages, or REM sleep. It has not been clinically validated to guide diagnosis or treatment.
No guaranteed outcome
A suggested bedtime or wake-up window does not guarantee that you will fall asleep, wake between cycles, feel refreshed, or obtain a particular amount or stage of sleep. Individual sleep need and sleep architecture vary.
When to seek professional help
Speak with a qualified clinician if sleep problems are persistent, distressing, or impair daytime functioning. Examples include loud or disruptive snoring, witnessed pauses in breathing, gasping during sleep, severe insomnia, unusual nighttime behavior, or ongoing excessive daytime sleepiness.
Safety first: do not drive or operate dangerous equipment when sleepy. If you may fall asleep while driving, stop in a safe place and get appropriate help rather than relying on a nap calculation.
Emergencies
This website is not an emergency service. If you believe you are experiencing a medical emergency, contact local emergency services immediately.
Caffeine and personal circumstances
The caffeine tool is a simplified decay model, not a blood test or dosing recommendation. Pregnancy, medications, smoking, liver function, genetics, and health conditions can affect caffeine clearance. Consult a healthcare professional for guidance specific to you.
Use of the site
You remain responsible for decisions made using the tools. By using Calculating Sleep, you acknowledge the limitations stated here and in the methodology.