📏 Growth Calculators

Track baby growth with height predictors, weight-for-age charts, head circumference, and BMI calculators.

All Growth Tools

Baby Height Predictor Predict your baby's adult height based on parental heights and current measurements using proven pediatric growth formulas. Growth Percentile Calculator Calculate your baby's height and weight percentile based on CDC/WHO growth charts for age and sex. Baby Weight-for-Age Calculator Check if your baby's weight is appropriate for their age using WHO weight-for-age growth standards. Baby Head Circumference Calculator Check your baby's head circumference against WHO growth standards to monitor healthy brain development. Baby BMI-for-Age Calculator Calculate your baby's BMI and compare it to age- and sex-specific CDC growth chart percentiles.

Understanding Baby Growth Charts

Growth charts plot a baby's measurements — weight, length, and head circumference — against reference data from large population studies. The WHO growth standards (used for children 0–2 years) are based on a multinational study of healthy breastfed infants raised in optimal conditions and represent how children should grow. The CDC growth charts (used for children 2–20 years in the United States) describe how children in the US actually grow. Percentiles indicate the percentage of same-age, same-sex children who measure below that value. A child at the 75th percentile for weight is heavier than 75% of their peers.

What Growth Percentiles Mean

Any percentile from the 3rd to the 97th is considered within the normal range. A baby consistently at the 10th percentile is not underweight — they are simply small. What matters most is consistent tracking along a growth curve over time. A sudden drop or rise of two or more major percentile lines (3rd, 10th, 25th, 50th, 75th, 90th, 97th) can indicate a feeding, absorption, or medical issue and should be evaluated by a pediatrician. Premature babies should be plotted on corrected age (subtract weeks of prematurity from chronological age) until 24–36 months.

Average Growth in the First Year

Newborns typically lose 5–10% of birth weight in the first few days due to fluid loss; this is normal and should be regained by 10–14 days. After that, healthy infants gain roughly 150–200 g (5–7 oz) per week for the first 3 months, then about 100–150 g (3–5 oz) per week from 3–6 months. Most babies double their birth weight by 4–6 months and triple it by 12 months. Length increases about 25 cm (10 in) in the first year, and head circumference grows approximately 12 cm (4.7 in). Head circumference reflects brain growth and is measured at every well-child visit in the first 2 years.

Predicting Adult Height

The mid-parental height method estimates a child's genetic potential for adult height by averaging the parents' heights and adjusting for sex. For boys: (father's height + mother's height + 13 cm) ÷ 2. For girls: (father's height + mother's height − 13 cm) ÷ 2. This gives a target height range of ±10 cm (4 inches) around the calculated value. Factors that can affect adult height include nutrition (especially in the first 1,000 days), chronic illness, hormonal conditions, and sleep quality, since the majority of growth hormone is released during deep sleep.