Average Weight for a 11-Month-Old Boy

The average (50th-percentile) weight for a 11-month-old boy is 9.4 kg (20.8 lb), based on the WHO Child Growth Standards. Across the healthy range, most boys this age weighs between 7.7 kg (16.9 lb) and 11.5 kg (25.4 lb).

What's typical at this age

Crawling, cruising and constant motion mean weight gain slows further. Many babies are around three times their birth weight by their first birthday. Appetite can swing from day to day. Between month 11 and month 12, the median boy gains roughly 236 g.

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.