Sleep schedule by age
How much sleep does a child need at which age, how many naps are usual and how long are they awake in between? The guideline values Moon Hour starts with – with sources.
How much sleep at what age
How much sleep a child needs per day in total was described in a consensus by American sleep medicine experts (AASM) in 2016; the WHO gives the same ranges in 2019. These are values for groups, not for an individual child. The number and length of naps are based on long-term studies (Iglowstein 2003, Weissbluth 1995, Staton 2020) that vary widely; the wake times are experience values. From this, the app calculates at the start:
| Age | Sleep per 24 hours | Night | Naps | Awake time in between |
|---|---|---|---|---|
| up to 4 months | 14–17 hr* | 11 hr | 4 × 45 min | 1 hr – 1 hr 30 min |
| 4–6 months | 12–16 hr | 11 hr | 3 × 1 hr | 1 hr 45 min – 2 hr 30 min |
| 6–9 months | 12–16 hr | 11 hr | 2 × 1 hr 15 min | 2 hr 30 min – 3 hr 30 min |
| 9–12 months | 12–16 hr | 11 hr | 2 × 1 hr 15 min | 3 hr – 4 hr |
| 12–15 months | 11–14 hr | 11 hr | 2 × 1 hr 15 min | 3 hr – 4 hr |
| 15–24 months | 11–14 hr | 11 hr | 1 × 2 hr | 5 hr – 5 hr 30 min |
| 2–3 years | 11–14 hr | 11 hr | 1 × 1 hr 45 min | 5 hr – 6 hr |
| from 3 years | 10–13 hr | 11 hr | 1 × 1 hr 25 min | 5 hr – 6 hr |
* The AASM gives no value for babies under 4 months; shown here is the National Sleep Foundation guideline (Hirshkowitz 2015).
The wake time runs from the first waking to the first nap (short value) up to the last one before the night (long value). Everything always fits into 24 hours – if you enter a different number of naps, the app shortens the wake times to match.
The midday nap is getting shorter
In a long-term study, two naps usually became one between 15 and 24 months (Weissbluth 1995). When the last one goes varies a lot: fewer than 2.5% of children stop before their second birthday, 94% by age five (Staton 2020). That's normal and not a sign that something is going wrong.
Fixed anchors
Bedtime stays between 6 pm and 9 pm, and in the morning the app suggests waking at the latest 45 minutes after your preferred getting-up time. In app data, toddlers' wake-up time stayed fairly stable on average over the first years (Mindell 2016).
What the app isn't
Moon Hour is a diary and planner that helps parents organise everyday life. Not a medical device; does not replace advice from a doctor or midwife. Moon Hour makes no health findings and doesn’t assess measurements. If something worries you, ask your pediatrician or midwife. For children under one year, the app gives no advice about milk at night.
Sources
- Paruthi et al. 2016: Recommended amount of sleep for children (AASM consensus)
- Hirshkowitz et al. 2015: National Sleep Foundation sleep duration guidelines
- WHO 2019: Guidelines on physical activity, sedentary behaviour and sleep for children under 5
- Iglowstein et al. 2003: Sleep duration from infancy to adolescence (Zurich Longitudinal Study)
- Weissbluth 1995: Naps in children (Sleep 18:82)
- Galland et al. 2012: Normal sleep patterns in infants and children
- Staton et al. 2020: Many naps, one nap, none (review)
- Mindell et al. 2016: Sleep development in the first years of life
General information, not a substitute for medical advice.
Sources checked: November 2026