Average Length for a 11-Month-Old Boy

The average (50th-percentile) length for a 11-month-old boy is 74.5 cm (29.3 in), based on the WHO Child Growth Standards. Across the healthy range, most boys this age measures between 70.2 cm (27.6 in) and 78.9 cm (31.1 in). (length is measured lying down until age 2)

What's typical at this age

By the first birthday many babies are about 50% longer than they were at birth. Length keeps climbing at around a centimetre a month. Between month 11 and month 12, the median boy grows about 1.2 cm.

A percentile compares your boy to other boys the same age — the 50th is simply the middle. Being above or below it is usually completely normal; a baby who has always tracked the 15th or 85th percentile is typically growing exactly as they should. What pediatricians watch for is a sudden change in the pattern, not the number itself.

Percentiles calculated from the WHO Child Growth Standards (2006). For information only — not medical advice. If you're concerned about your child's growth, speak to your pediatrician or health visitor. Full disclaimer.