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Child Growth Calculator: Tracking Height, Weight, and Percentiles

Understand growth percentiles, the WHO and CDC growth charts, and what it means if your child is above or below average for their age.

Child Growth Calculator: Tracking Height, Weight, and Percentiles

Child Growth Charts: Percentiles Explained

Growth charts plot a child's height, weight, and head circumference against standardised reference populations. The result is a percentile — if your child is at the 60th percentile for height, they are taller than 60% of children of the same age and sex.

WHO vs CDC Growth Charts

  • WHO charts (0–5 years): Based on healthy, breastfed children in optimal conditions across 6 countries. Recommended by the AAP for children under 2.
  • CDC charts (2–20 years): Based on US population data. Used for older children and adolescents.

What Percentiles Mean

Any percentile between 5th and 95th is considered within the normal range. What matters most is consistency — a child tracking steadily at the 10th percentile is growing normally; a child whose percentile drops sharply across two visits warrants investigation.

Key Milestones

  • Most babies double their birth weight by 5 months
  • Most babies triple their birth weight by 12 months
  • Height at age 2 is roughly 50% of adult height
  • Girls typically finish growing by age 16; boys by age 18

BMI in Children

For children, BMI is not interpreted using adult cut-offs. A BMI at or above the 95th percentile for age and sex is classified as obese; at or above 85th percentile is overweight.

Track your child's growth: Free Child Growth Calculator