Your baby at 8 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 8 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 | 8.62 kg | 8.01–9.27 kg | 7.95 kg | 7.33–8.64 kg |
| Length | 70.6 cm | 69.1–72.1 cm | 68.8 cm | 67.2–70.4 cm |
| Head circumference | 44.5 cm | 43.7–45.4 cm | 43.4 cm | 42.5–44.3 cm |
Want the number for your own baby? Open the percentile calculator
Sleep at 8 months
Ranges, not targets. Healthy babies sit outside them regularly.
- Total per day
- 12 h – 16 h
- One nap
- 1 h – 2 h
- 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.
- Sits unsupportedGross motorusual window: 4.5–8
- CrawlsGross motorusual window: 6–11
- First stepsGross motorusual window: 8.2–17.6
- Pincer graspFine motorusual window: 7–12
- BabblesSpeechusual window: 4–9
- Waves bye-byeSocialusual window: 8–14
- Object permanenceCognitiveusual window: 7–12
Reference figures, not medical advice. Every baby differs; a check-up answers questions a table cannot.