The most complete free sleep resource online — breathing timers, white noise, sleep diary, clinical calculators, and neuroscience guides. No signup, no ads.
Best bedtime or wake time — 90-min cycles
What time to go to sleep tonight?
Best wake times from right now
When you enter REM each cycle
N3 slow-wave sleep by age and cycles
Weekly deficit and recovery plan
Cognitive impairment with BAC equivalent
Personalized weekly sleep schedule
Right dose and timing for your goal
How tonight's drinks affect your sleep
Night shift and rotating schedule optimizer
Power nap, NASA nap, or full cycle
When caffeine clears your system tonight
Morning lark or night owl? Peak hours
Peak focus, exercise, sleep by chronotype
Day-by-day recovery by time zones
WHO standards with healthy range
4 medical formulas — Hamwi, Devine, Robinson
Daily calorie needs — Mifflin-St Jeor
Protein, carbs, fat targets for your goal
Daily protein needs by weight and goal
5 training zones — Karvonen method
Calories burned walking by weight
Daily hydration by weight and activity
US Navy method — no calipers needed
MySleepTool.com is the most complete free sleep resource on the internet. Whether you are struggling with insomnia, trying to fix your sleep schedule, recovering from jet lag, working night shifts, parenting a newborn, or simply want to understand your sleep better — you will find a free, science-backed tool here for exactly that problem. Every tool runs entirely in your browser with no account required and no data collected.
If you're reading this at 2 or 3 AM unable to sleep, the Can't Sleep guide is built specifically for you. Answer 3 quick questions about what's keeping you awake and get an immediate personalized plan — whether it's anxiety, racing thoughts, middle-of-the-night waking, or hyperarousal. The guide uses stimulus control, 4-7-8 breathing, and PMR — the three most evidence-based interventions for acute sleeplessness.
For an even more immersive experience, the Sleep Mode tool gradually dims your screen, slows your breathing guide, and fades in ambient sound — designed to drift you off without you having to do anything. Just lie down and let it work.
Our Sleep Cycle Calculator uses the 90-minute sleep architecture model to find bedtimes and wake times aligned with your natural cycles — so you wake at the end of a cycle feeling refreshed, not in the middle of deep sleep feeling groggy. The If I Sleep Now Calculator tells you exactly what time to set your alarm based on falling asleep right now.
The Sleep Debt Calculator tracks your cumulative weekly deficit and gives you a recovery plan. The Sleep Deprivation Calculator converts your deficit into cognitive impairment equivalents — including the blood alcohol equivalent of your current sleep state. After 17 hours awake, impairment equals a BAC of 0.05%.
The 4-7-8 Breathing Timer guides you through Dr. Andrew Weil's breathing technique with animated visual cues and sound tones — four cycles takes 90 seconds and measurably lowers heart rate. The White Noise Generator produces six sleep sounds in your browser using the Web Audio API — no downloads, no subscriptions, sleep timer included.
The PMR Guide takes you through a complete body scan with automatic timers — one of the core techniques of CBT-I, the most effective treatment for chronic insomnia. The Sleep Diary lets you log every night and see weekly patterns — essential for anyone working through insomnia.
The Insomnia Severity Calculator implements the validated ISI (Insomnia Severity Index) — the same 7-question screening tool used by sleep specialists worldwide, with original scoring cutoffs. The Sleep Apnea Risk Calculator uses the STOP-BANG questionnaire — the gold standard for OSA screening used in hospitals globally. Both provide not just a score but personalized next steps.
The Baby Sleep Calculator covers newborn to 24-month sleep, calculates wake windows by age, and generates a complete daily schedule aligned with AAP safe sleep guidelines. Parents of newborns also benefit from our Sleep Debt Calculator — new parents accumulate sleep debt faster than almost any other group.
The Jet Lag Calculator generates a day-by-day recovery plan based on time zones and direction of travel, with light exposure and melatonin timing. The Melatonin Calculator shows the research-backed dose (0.3–0.5mg — most OTC doses are 10–20× too high) and exact timing for your specific goal. The Alcohol and Sleep Calculator shows how tonight's drinks affect your REM sleep, deep sleep, and 3 AM wake risk in real time.
The Shift Work Calculator optimizes sleep windows for night shift and rotating shift workers — the population at highest sleep health risk. The Circadian Rhythm Calculator maps your entire day based on your chronotype, including peak cognitive performance, exercise window, caffeine cutoff, and wind-down timing.
All tools are 100% free, run in your browser, and require no personal information. We are not affiliated with any supplement company, mattress brand, or sleep clinic. Our content is built on peer-reviewed research from AASM, NSF, and leading sleep journals. Every page is reviewed every 6 months. Learn more about our methodology and team →