🌙Baby Sleep Calculator

About this tool

Enter your baby's age in months and the time they usually wake in the morning. The tool shows typical wake windows, the number of naps and total sleep for that age, then builds a sample day with nap times and a bedtime. It flags a bedtime outside the usual 6:00–8:30 pm range. Nothing is stored.

How baby sleep changes with age

A wake window is how long a baby can comfortably stay awake between sleeps before becoming overtired. It grows quickly. Newborns manage only 35–60 minutes, 3–4-month-olds about 1¼–2 hours, 5–7-month-olds 2–3 hours, and toddlers on one nap five hours or more. Naps consolidate as wake windows grow: four or more for young babies, three by about five months, two from around eight months, and one from about 15–18 months. Total sleep guidance from the American Academy of Sleep Medicine and the US National Sleep Foundation is 14–17 hours for newborns, 12–16 hours (including naps) for 4–12 months and 11–14 hours for 1–2-year-olds. In the example, a 6-month-old who wakes at 07:00 naps around 09:15 and 13:00, has a short catnap at 16:30 and goes to bed around 19:15. Honest limits: these are averages, not rules. Every baby is different, growth spurts, illness and teething disrupt sleep, and newborns don't follow schedules at all. Watch for sleepy cues such as eye rubbing, staring, yawning and fussing. Always follow safe sleep advice: on their back, in a clear cot or Moses basket, in your room for the first six months. Talk to your health visitor or doctor if you're concerned. The baby tracker and the baby age calculator are related, and Sleep cycles, and waking up less awful covers adult sleep cycles.

Frequently asked questions