Child Growth Percentile Calculator

Growth percentiles compare your child's measurements to other children of the same age and sex. If your child is at the 75th percentile for height, they're taller than 75% of children their age. Percentiles between 5th and 95th are typically considered normal. What matters most isn't a specific number, but that your child follows their own consistent growth curve over time. A child consistently at the 25th percentile is healthy—sudden jumps or drops across multiple percentiles may warrant discussion with your pediatrician.

WHO charts (used for ages 0-2) are based on breastfed infants from six countries and represent optimal growth standards. CDC charts (used for ages 2-20) are reference charts based on how American children actually grew in the 1970s-90s. WHO charts tend to show breastfed babies as heavier initially and leaner after 6 months compared to CDC charts. Most pediatricians use WHO for infants under 2, then switch to CDC charts. The differences are usually small but can affect percentile readings.

Consult your pediatrician if: your child's weight or height falls below the 5th or above the 95th percentile, there's a sudden change of two or more percentile lines (e.g., dropping from 50th to 10th), weight and height percentiles are very different (e.g., 90th for weight but 20th for height), or growth appears to plateau for several months. Single measurements matter less than patterns over time. Your pediatrician will track growth trends and consider factors like genetics, prematurity, and overall health.

Growth percentiles provide clues but don't directly predict adult height. A child at the 90th percentile won't necessarily be a tall adult—growth rates vary, especially during puberty. Better predictors include: mid-parental height formula (average parents' heights, then add 2.5 inches for boys or subtract for girls), bone age X-rays, and growth velocity. Children often experience growth spurts at different ages, so a currently shorter child may catch up during adolescence. Genetics accounts for about 80% of adult height.

Unlike adults, children's healthy BMI changes significantly with age and differs between boys and girls. A BMI of 18 might be overweight for a 5-year-old but underweight for a teenager. BMI percentiles account for these normal variations by comparing children to others of the same age and sex. For children, underweight is below 5th percentile, healthy weight is 5th-85th, overweight is 85th-95th, and obesity is 95th or above. This age-adjusted approach provides more accurate assessment than fixed BMI cutoffs used for adults.