What is a wake window and why does it matter?

A wake window is the amount of time your baby can comfortably stay awake between sleep periods. Think of sleep pressure like a balloon filling with air — the longer your baby is awake, the more the balloon fills. Wake windows define how long before the balloon is "full enough" for good sleep, but before it overinflates into overtiredness. Catching your baby at the right moment in the window makes settling faster, naps longer, and nights better.

How many naps should my baby have?

Nap count decreases predictably with age. Newborns nap 5–7 times per day; by 6 months most babies are on 2 naps; most toddlers drop to 1 nap between 14–18 months; and most children stop napping altogether between 3–5 years. Individual variation is wide — some babies consolidate to fewer naps earlier than average, while others hold on to an extra nap longer. The key sign a nap transition is ready is that your baby consistently fights a particular nap for 2+ weeks while remaining well-rested on fewer naps.

What time should my baby go to bed?

Earlier than most parents expect. Babies and toddlers aged 4 months to 3 years typically thrive with a 6:30–7:30pm bedtime. This isn't a cultural preference — it's driven by the fact that melatonin (the sleep hormone) production peaks in the early evening for young children. Keeping babies up late hoping they'll "sleep in" usually backfires; overtiredness makes cortisol spike, which actually disrupts sleep and causes earlier waking.

My baby fights naps. What should I do?

Nap resistance is almost always one of three things: (1) the wake window is too short — the baby isn't tired enough; (2) the wake window is too long — the baby is overtired and cortisol is spiking; or (3) a nap transition is happening — the baby is developmentally dropping a nap. Use this tool to check if the timing looks right for your baby's age, and adjust in 15-minute increments. A consistent pre-nap routine (2–3 minutes of the same sequence every time) also helps signal sleep.

What is the 2-to-1 nap transition and when does it happen?

The 2-to-1 nap transition is when a toddler moves from two naps to one. Most children are ready between 14–18 months, though some transition as early as 12 months and some hold two naps until 18–20 months. Signs it's time: consistently refusing the second nap, or taking the second nap so late that bedtime gets pushed very late. The transition period can take 2–6 weeks and is often bumpy — a "split schedule" alternating one-nap and two-nap days is common during the switch.

Should I wake my baby from a nap?

Yes, in most cases. Capping naps is important to protect night sleep and maintain consistent wake windows. For babies under 3 months, let naps run — they need the sleep. For babies 3 months and older, most sleep consultants recommend capping the last nap of the day (the "cat nap" for babies on 3 naps, or the afternoon nap for babies on 2 naps) to protect the bedtime window. For toddlers on 1 nap, waking by 3pm helps protect a 7–7:30pm bedtime.

How accurate is the schedule this tool generates?

The schedule is a research-based starting point, not a prescription. It uses age-appropriate wake windows and distributes them across your chosen wake time and bedtime. Every child is different — you may need to nudge nap times by 15–30 minutes to find what works best for your baby. Watch your baby's cues (yawning, eye-rubbing, zoning out) and adjust from there. This tool gives you the framework; you tune it to your child.

Baby Sleep Schedule Builder

Build a personalised nap and bedtime schedule — with age-appropriate wake windows — for your baby or toddler.

How to Use Wake Windows

Wake windows are the single most useful concept in infant sleep. They explain why your baby may fight naps sometimes and not others, why bedtime works brilliantly some nights and falls apart on others, and why "just put them down earlier" sometimes helps and sometimes makes things worse.

The mechanics are simple. Sleep pressure (adenosine) builds in the brain the longer a baby is awake. Wake windows define the Goldilocks zone — long enough for adequate sleep pressure, short enough to stay below the overtiredness threshold where cortisol spikes and actually makes sleep harder. Catch your baby in that window and settling is easier, naps run longer, and nights improve.

Wake windows grow with age. A newborn can only manage 45–60 minutes awake; a 12-month-old can handle 3–4 hours. This is why a schedule that worked brilliantly at 4 months suddenly "stops working" — the baby's capacity grew but the schedule didn't. Rebuilding the schedule every 4–8 weeks (or sooner after a regression) keeps you in sync with your child's development.

The last wake window before bed is critical. It typically needs to be slightly longer than the others — this is when you want the sleep-pressure balloon to be as full as possible before bed. An undertired child at bedtime will fight sleep or wake frequently overnight as sleep pressure doesn't carry them through.

Wake Windows by Age — Quick Reference

Age	Naps	Wake windows	Day sleep
0–2 months	4–7	45–55 min	5–8 hr
2–4 months	3–5	60–80 min	4–6 hr
4–6 months	3–4	90–110 min	3–5 hr
6–9 months	2–3	150–180 min	2.5–4 hr
9–14 months	1–2	195–225 min	2–3.5 hr
14–18 months	1–2	270–270 min	1.5–3 hr
18 months–3 years	0–1	300–300 min	1–2.5 hr
3–5 years	0–1	420–420 min	0–1.5 hr

Sleep Schedule Builder — Frequently Asked Questions

Sources & Methodology

Last reviewed: October 17, 2026

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How to Use Wake Windows

Wake Windows by Age — Quick Reference

Sleep Schedule Builder — Frequently Asked Questions

Sources & Methodology

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