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NapCue

Free baby nap calculator

Baby wake window calculator

Find a flexible starting point for your baby’s next nap based on their age and when they last woke. Free to use, with no account needed.

Find the next nap window

When did your baby last wake up?

Use the time your baby woke from their last sleep, including their morning wake-up.

The calculation runs in your browser.

Disclaimer: This calculator provides general estimates for informational purposes only. It is not medical advice. Your baby’s needs may vary; follow their cues and your clinician’s guidance.

How the baby nap calculator works

A wake window is the time your baby is awake between periods of sleep. This calculator uses your baby’s age to select a general wake-window range, then adds that range to the time they last woke.

Babies have different sleep needs, and those needs can change from day to day. The result is a flexible starting point—not a prediction of exactly when your baby will fall asleep.

The ranges used by this calculator are general estimates. They are not medical rules, and this tool does not replace advice from your baby’s clinician.

Frequently asked questions

What is a baby wake window?
A wake window is the time your baby is awake between periods of sleep. It starts when your baby wakes and ends when they fall asleep again.
What if my baby’s nap window has already passed?
The estimate may not match your baby’s needs, or the wake time you entered may need updating. If your baby seems ready for sleep, follow their cues.
Should the next wake window change after a short nap?
A short nap doesn’t tell you exactly when the next nap should be. Watch your baby’s cues and use the estimate flexibly. This calculator does not currently adjust its estimate based on nap length.
Can I use this calculator for a newborn?
Newborn sleep can be unpredictable. Follow your baby’s feeding and sleep guidance from their clinician, and treat this estimate as a flexible starting point.
Does this calculator tell me when bedtime should be?
This tool estimates a next nap window; it does not calculate bedtime.
What if I’m concerned about my baby’s sleep?
Contact your baby’s clinician if you have concerns about sleep, breathing, feeding, growth, or illness.

A note on safe sleep

For naps and nighttime sleep, place your baby on their back on a firm, flat, separate sleep surface. Keep the sleep space free of loose bedding and soft objects.

Read the American Academy of Pediatrics’ safe sleep guidance

Keep track of the bigger picture

Log naps and spot sleep patterns with NapCue.

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