How much should a 1-year-old baby weigh?

There's quite a bit of individual variation in 1-year-old babies' weight—that's why everyone has something different to say about it. To give you a general sense, according to the World Health Organization (WHO) reference standards, an average 12-month-old girl weighs around 8.9 kg and a boy around 9.6 kg. But "average" only describes the middle of a baby population—the healthy range is much broader than that (approximately 7-11 kg in girls, 7.5-12 kg in boys).

So what really matters isn't a single number, but your baby's own growth curve: has he been gaining weight consistently since birth, and is his height progressing in parallel? If he's tracking along a line that your doctor calls "good progress" at monthly checkups, you don't need to compare your baby's weight to anyone else's. Only if weight gain has stopped or gone backward in recent months would I suggest talking to your pediatrician.