0–36 months · compiled September 2026 · cues outrank the clock
Wake window calculator — when is the next nap?
Pick your baby's age, enter when they woke up, and get the wake-window range for that age plus the clock times for the next nap and bedtime. General guidance compiled from major pediatric sleep resources — no signup, nothing uploaded.
Accepts 7:05 AM, 7:05 pm, or 19:05.
Wake window
1 h 15 min–1 h 45 min
4 months · typical range
Next nap — window opens
8:15 AM
after 1 h 15 min awake
Next nap — window closes
8:45 AM
past this, overtiredness builds
Bedtime rule: last nap end + this age's final window (1 h 45 min) — the bedtime calculator works it out for you. This is general guidance for 4 months — sleep cues (yawning, staring, rubbing eyes) outrank the clock.
All 13 calculators
Three main tools plus one page per age — each locked onto that month's typical windows.
3-Month-Old Wake Windows
Window: 1 h–1 h 30 min
4-Month-Old Wake Windows
Window: 1 h 15 min–1 h 45 min
5-Month-Old Wake Windows
Window: 1 h 30 min–2 h 15 min
6-Month-Old Wake Windows
Window: 2 h 15 min–2 h 45 min
7-Month-Old Wake Windows
Window: 2 h 30 min–3 h 15 min
8-Month-Old Wake Windows
Window: 2 h 30 min–3 h 15 min
9-Month-Old Wake Windows
Window: 3 h–3 h 30 min
10-Month-Old Wake Windows
Window: 3 h–3 h 30 min
12-Month-Old Wake Windows
Window: 3 h 15 min–4 h
18-Month-Old Wake Windows
Window: 4 h–5 h
Wake Window Calculator
Pick your baby's age, enter when they woke up, and get the wake-window range plus the clock times for the next nap and bedtime.
Nap Schedule Generator
Enter your baby's age and wake-up time — get a full-day nap schedule with clock times for every nap and bedtime.
Baby Bedtime Calculator
Enter your baby's age and the time the last nap ended — get the bedtime window that fits the age's final wake window.
Guides
What Are Wake Windows?
The plain-English definition of wake windows, why they work, and how to spot them in your own baby's day.
Wake Windows by Age
The full chart: wake windows, nap counts, and total sleep for every age from newborn to 3 years.
Overtired vs Undertired
The two look identical at naptime — here's how to tell them apart and fix each one differently.
Nap Transition Guide
The three big nap drops — 4→3, 3→2, 2→1 — with the signs, timing, and the messy-weeks playbook for each.
What this site does — and what it does not
It does
- Turn your baby's age and wake-up time into clock-time nap and bedtime windows.
- Show the age-typical range — not one magic number — and say where it comes from.
- Keep every calculation in your browser; nothing you type is stored or sent.
It does not
- Replace your pediatrician — persistent sleep problems deserve real medical advice.
- Know your baby better than you do — sleep cues outrank every number here.
- Guarantee naps — teething, leaps, and plain bad days exist; the frame bends, not you.