Your baby at 15 months
Everything that lines up at this one age — growth figures from the WHO standard, sleep norms, the milestones whose normal window covers this month, and the vaccine doses due. Percentiles are called centiles in the UK; the numbers are identical.
Growth at 15 months
Median means half of babies are above and half below. Being away from the median is not a problem in itself — following your own curve is what matters.
| Median (50th) · Boys | Middle half (25th–75th) · Boys | Median (50th) · Girls | Middle half (25th–75th) · Girls | |
|---|---|---|---|---|
| Weight | 10.31 kg | 9.57–11.11 kg | 9.60 kg | 8.85–10.44 kg |
| Length | 79.2 cm | 77.5–80.9 cm | 77.5 cm | 75.7–79.4 cm |
| Head circumference | 46.8 cm | 45.9–47.7 cm | 45.7 cm | 44.7–46.6 cm |
Want the number for your own baby? Open the percentile calculator
Sleep at 15 months
Ranges, not targets. Healthy babies sit outside them regularly.
- Total per day
- 11 h – 14 h
- One nap
- 1 h – 1 h 30 m
- Night sleep
- 10 h – 12 h
Milestones in this window
The window is when a skill usually appears — not a deadline. Appearing later than the window is a reason to mention it at a check-up, not to worry alone.
- Stands aloneGross motorusual window: 9–15
- First stepsGross motorusual window: 8.2–17.6
- Walks wellGross motorusual window: 12–20
- Stacks 2 blocksFine motorusual window: 12–18
- ScribblesFine motorusual window: 12–24
- First wordSpeechusual window: 9–15
- Plays pretendSocialusual window: 14–24
- Points to picturesCognitiveusual window: 12–20
Vaccine doses at this age
Routine doses only, from the national schedules as published by each country's health authority. Vaccinations always follow chronological age, even for premature babies.
United States
- DTaPdose 4
Reference figures, not medical advice. Every baby differs; a check-up answers questions a table cannot.