Not Medical Advice
This tool provides general educational estimates based on typical sleep-cycle averages. It is not medical advice. If you have ongoing sleep problems, please consult a qualified doctor.
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Your Data Stays on Your Device
Everything you enter — sleep times, diary entries, schedules — is saved only in your browser's local storage. Nothing is uploaded to any server. We never see your data.
💤 Nap Optimizer
💤 Nap Optimizer — How to Use
What This Tool Does
The Nap Optimizer finds the ideal nap length and timing so you wake at a natural sleep cycle boundary — refreshed instead of groggy.
When to Use It
Any time you need a strategic nap: before a night shift, during a low-energy afternoon, or after poor sleep.
Fields Explained
Current Time
The time right now — when you can start the nap.
Need Alert By
The earliest time you must be fully functional again.
Tiredness Level
How tired you feel right now. More tired = longer nap recommended.
Important Task After?
If yes, the calculator avoids deep-sleep naps that cause grogginess.
Reading the Result
Your nap type (Power / Recovery / Full Cycle), start time, and wake alarm time. Also explains why other lengths are not ideal right now.
Pro Tips
10–20 min: light refresh, no grogginess. Best for a work break.
90 min: full sleep cycle, best recovery. You need at least 2 hours available.
Avoid napping after 3 PM — it can delay night-time sleep.
Always set a real alarm. Oversleeping a nap causes worse grogginess than skipping it.
Try a Sample
Sample scenario
It is 1:00 PM, you need to be alert again by 5:00 PM, and you are exhausted.
Expected result: 90-min Full Cycle Nap · Start 1:05 PM · Alarm 2:35 PM
😴 Science-Based Nap Calculator
Nap Optimizer
Not all naps are equal. A 26-minute nap and a 90-minute nap produce completely different outcomes. Enter your situation and get the exact nap length, best start time and wake alarm — engineered around your sleep cycles.
Nap recommendations are based on sleep cycle science and adenosine research. Individual results vary. If you experience persistent daytime sleepiness despite adequate nighttime sleep, consult a doctor to rule out sleep disorders.