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Baby Height Percentile Calculator

Height/Length Percentile by Age

Compare your baby's length to WHO growth standards

Formula

Z-Score = (Length - WHO Median) / SD | SD ≈ 4% of median length | Length: inches × 2.54 = cm. Percentile ranges estimated from z-score.

Frequently Asked Questions

How is baby length measured?
For babies under 2 years, length is measured while lying down (recumbent length). For children 2 and older, height is measured while standing. Recumbent length is typically about 1 cm longer than standing height.
When should I be concerned about my baby's length?
Most babies grow at their own pace. Concern arises when length falls below the 3rd percentile, above the 97th, or when there is a significant change in growth trajectory (crossing two or more percentile lines). Your pediatrician monitors these trends.
Does birth length predict adult height?
Birth length is a poor predictor of adult height. Genetics, nutrition, and overall health play much larger roles. By age 2, a child's height percentile becomes a somewhat better predictor, but many factors can change the outcome.

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