Newborn weight, length and head size
On the WHO growth charts, the median weight at birth is 3.3 kg (7.4 lb) for boys and 3.2 kg (7.1 lb) for girls. Most children of this age, between the 3rd and 97th percentiles, weigh 2.5–4.3 kg (5.5–9.6 lb) if they are boys or 2.4–4.2 kg (5.4–9.2 lb) if they are girls.
The median length at birth is 49.9 cm (19.6 in) for boys and 49.1 cm (19.3 in) for girls; between the 3rd and 97th percentiles it ranges over 46.3–53.4 cm (18.2–21.0 in) for boys and 45.6–52.7 cm (18.0–20.7 in) for girls. The median head circumference is 34.5 cm (13.6 in) for boys and 33.9 cm (13.3 in) for girls.
WHO percentiles at birth
| P3 | P15 | P50 | P85 | P97 | |
|---|---|---|---|---|---|
| Weight (kg) Boys | 2.5 | 2.9 | 3.3 | 3.9 | 4.3 |
| Weight (kg) Girls | 2.4 | 2.8 | 3.2 | 3.7 | 4.2 |
| Length (cm) Boys | 46.3 | 47.9 | 49.9 | 51.8 | 53.4 |
| Length (cm) Girls | 45.6 | 47.2 | 49.1 | 51.1 | 52.7 |
| Head circumference (cm) Boys | 32.1 | 33.1 | 34.5 | 35.8 | 36.9 |
| Head circumference (cm) Girls | 31.7 | 32.7 | 33.9 | 35.1 | 36.1 |
These are WHO reference values, not targets: a healthy child can sit anywhere on the chart, and growth over time matters more than one measurement. Values outside the 2nd and 98th percentile lines are worth discussing with a doctor.
Work out your child's exact percentile
Frequently asked questions
How much should a newborn weigh?
On the WHO charts, the median weight at birth is 3.3 kg (7.4 lb) for boys and 3.2 kg (7.1 lb) for girls; the 3rd to 97th percentiles span 2.5–4.3 kg (5.5–9.6 lb) for boys and 2.4–4.2 kg (5.4–9.2 lb) for girls.
How long should a newborn be?
The median length at birth is 49.9 cm (19.6 in) for boys and 49.1 cm (19.3 in) for girls; the 3rd to 97th percentiles span 46.3–53.4 cm (18.2–21.0 in) for boys and 45.6–52.7 cm (18.0–20.7 in) for girls.
What head circumference is normal at birth?
The WHO median head circumference at birth is 34.5 cm (13.6 in) for boys and 33.9 cm (13.3 in) for girls, with 3rd to 97th percentiles of 32.1–36.9 cm (12.6–14.5 in) and 31.7–36.1 cm (12.5–14.2 in).
Other ages
- Newborn
- 1 month
- 2 months
- 3 months
- 4 months
- 5 months
- 6 months
- 7 months
- 8 months
- 9 months
- 10 months
- 11 months
- 12 months
- 13 months
- 14 months
- 15 months
- 16 months
- 17 months
- 18 months
- 19 months
- 20 months
- 21 months
- 22 months
- 23 months
- 24 months
- 3 years
- 4 years
- 5 years
Sources
- WHO: Child growth standards (weight-for-age, length/height-for-age, head circumference-for-age)
- Grummer-Strawn LM, Reinold C, Krebs NF. Use of World Health Organization and CDC growth charts for children aged 0–59 months in the United States. MMWR Recomm Rep 2010;59(RR-9)
- NHS: Your baby's weight and height