Baby Growth Calculators & Guides

Track your baby's incredible growth with standard WHO/CDC percentile calculators, milestone trackers, and expert guides on their beautiful developmental leaps. From birth through the toddler years, these tools help you visualize how your child measures against age-matched reference populations — the same data your pediatrician reviews at every well-child visit.

The World Health Organization growth standards (used for children 0–23 months) are based on healthy breastfed infants across six countries, while CDC growth charts (used from age 2 onward) draw on U.S. population data. Both systems express measurements as percentiles — a baby at the 40th percentile for weight, for example, weighs more than 40% of same-age peers. What matters most is not the specific number but the trend over time: steady tracking along a curve signals healthy growth.

Beyond physical measurements, developmental milestones — rolling over, babbling, first steps — follow their own timeline. Our milestone tracker uses the CDC 2022 guidelines to show which motor, cognitive, language, and social skills are expected at each age, helping you celebrate progress and spot areas worth discussing with your pediatrician.