One chart rarely tells the whole story. In the first year, four WHO curves work together, and reading them as a set is how pediatricians think.
Weight-for-age
The fast-moving curve, sensitive to feeding and illness. It responds quickly, which makes it the early-warning measure.
Length-for-age
The slow, steady curve that reflects long-term nutrition and genetics. Length problems appear late but matter most for the long run.
Head circumference and BMI
Head circumference tracks brain growth — fastest of all in year one. BMI-for-age balances weight against length and rounds out the picture.
Four curves, one story
GrowChart plots all four WHO curves for the first year on one timeline, so the whole story is visible at every checkup.
Try the free calculator
No sign-up needed — check a percentile or z-score in seconds, then save & track when you create a free account.
Open the calculator → Create a free account