The WHO growth charts for girls track length, weight, head circumference, and BMI from birth through age 19. They remain the current global standard, built from data on approximately 8,500 children across six countries (Brazil, Ghana, India, Norway, Oman, and the United States). Here’s what the numbers look like at key ages and how to make sense of them.
How WHO Charts Differ From CDC Charts
The WHO charts use breastfed infants as the baseline for normal growth. Every infant in the WHO sample was breastfed for at least 12 months and predominantly breastfed for at least four months. The CDC charts, by contrast, were built from a general U.S. population where only about 50% of infants were ever breastfed, and just 33% were still breastfeeding at three months. That means the CDC charts largely reflect formula-fed growth patterns.
This matters because breastfed and formula-fed babies grow differently. Breastfed infants tend to gain weight more slowly after the first few months, which can look like faltering growth on a CDC chart when the baby is actually growing normally. In the U.S., the CDC recommends using the WHO charts for all children under age 2, regardless of how they’re fed.
Girls’ Length by Age: Birth to 2 Years
Length is measured lying down (recumbent) until age 2, then standing height is used from age 2 onward. The table below shows length in centimeters at five standard percentile lines.
- Birth: 3rd percentile: 45.6 cm, 15th: 47.2 cm, 50th: 49.1 cm, 85th: 51.1 cm, 97th: 52.7 cm
- 6 months: 3rd: 61.5 cm, 15th: 63.4 cm, 50th: 65.7 cm, 85th: 68.1 cm, 97th: 70.0 cm
- 12 months: 3rd: 69.2 cm, 15th: 71.3 cm, 50th: 74.0 cm, 85th: 76.7 cm, 97th: 78.9 cm
- 24 months: 3rd: 80.3 cm, 15th: 83.1 cm, 50th: 86.4 cm, 85th: 89.8 cm, 97th: 92.5 cm
A girl at the 50th percentile is about 49 cm (19.3 inches) at birth and reaches roughly 86 cm (34 inches) by her second birthday. That’s nearly doubling in length over two years. The biggest growth spurt happens in the first six months, when a typical girl adds about 16 to 17 cm.
What the Percentiles Actually Mean
If your daughter is at the 15th percentile for length, that means 15% of healthy girls her age are shorter than she is and 85% are taller. Being at the 15th percentile is not a problem on its own. The WHO charts represent a range of healthy growth, and children at the 3rd percentile can be just as healthy as those at the 97th.
What matters more than any single percentile is whether your child stays on a consistent curve over time. A girl who has tracked along the 25th percentile since birth is growing predictably. A girl who drops from the 75th to the 15th over several months is showing a change that deserves attention. The clinical rule of thumb: crossing two major percentile lines (for example, dropping from the 50th past the 15th down to the 3rd) is considered significant enough to evaluate, especially after 24 months of age.
Key Thresholds That Flag Concerns
The WHO charts use specific cutoffs to identify potential growth problems in girls from birth to age 2:
- Underweight: weight-for-age below the 3rd percentile
- Stunted: length-for-age below the 3rd percentile
- Wasted: weight-for-length below the 3rd percentile, which can signal recent nutritional problems or illness
- Risk of overweight: weight-for-length above the 85th percentile
- Overweight: weight-for-length above the 97th percentile
A child who is short but whose parents are also short may simply have a genetic growth pattern, not a nutritional issue. These thresholds are starting points for conversation, not automatic diagnoses. Context always matters.
Head Circumference: Birth to 2 Years
Head circumference is tracked alongside length and weight in the first two years because it reflects brain growth. On the WHO chart for girls, the 50th percentile head circumference starts near 34 cm at birth and increases to roughly 48 cm by age 2. Growth is fastest in the first year, with head circumference increasing by about 10 to 12 cm. The same principle of following a consistent curve applies here. A head that is large or small but growing steadily along its percentile line is typically normal.
Ages 2 to 5: The Shift to BMI
After age 2, the WHO charts shift from weight-for-length to BMI-for-age as the main indicator of body proportion. Standing height replaces recumbent length. For girls, the 50th percentile BMI values are remarkably stable during this period:
- Age 2: BMI of 15.7 (97th percentile: 18.5)
- Age 3: BMI of 15.4 (97th percentile: 18.2)
- Age 4: BMI of 15.3 (97th percentile: 18.3)
- Age 5: BMI of 15.3 (97th percentile: 18.6)
It’s normal for BMI to dip slightly between ages 2 and 5 before rising again. This pattern, called the “adiposity rebound,” typically happens around age 5 or 6. A BMI above the 85th percentile signals risk of overweight, and above the 97th percentile is classified as overweight in this age range.
Ages 5 to 19: A Separate Reference
The WHO publishes a separate growth reference for children and adolescents aged 5 to 19. It covers three indicators: height-for-age, weight-for-age (up to age 10 only), and BMI-for-age. Weight-for-age is dropped after age 10 because the wide variation in pubertal timing makes raw weight a poor indicator of health. BMI-for-age becomes the primary tool for assessing body proportion through adolescence.
The thresholds also shift slightly for this age group. Overweight is defined as BMI-for-age above the 85th percentile (rather than the 97th used for younger children), and obesity is above the 97th percentile. Stunting is still defined as height-for-age below the 3rd percentile.
Tips for Tracking Growth at Home
You can download the official WHO percentile charts as free PDFs from the WHO website and plot your daughter’s measurements yourself. A few practical points make the numbers more reliable.
For children under 2, length should be measured lying flat on a firm surface. Standing height measurements in toddlers can be 1 to 2 cm shorter than lying-down measurements simply because of gravity compressing the spine, and the WHO charts account for this by switching measurement methods at age 2. Weigh infants without clothes or a diaper for consistency. Take head circumference by wrapping a flexible tape measure around the widest part of the head, just above the eyebrows and ears.
Plotting a single point tells you where your child falls today. Plotting several points over months gives you the growth trajectory, and trajectory is what really matters. A child who is consistently small is following her own curve. A child whose curve is flattening or dropping is the one who needs a closer look.