A 4-month-old baby typically weighs around:

• Baby boys: Approximately 6.7 kg (14.8 lbs)
• Baby girls: Approximately 6.2 kg (13.7 lbs)

This is based on the 50th percentile average weight from growth charts by the World Health Organization and other reputable sources

. Other sources report similar averages, with baby boys around 15 lbs (6.8 kg) and baby girls around 13.8 to 15.7 lbs (6.3 to 7.1 kg) at 4 months

. It's important to note that healthy babies can vary in size, and steady growth along their own percentile curve is more important than hitting an exact weight. If concerned, consulting a pediatrician or health visitor is recommended