Is 20%-30% average for height?

Question

My husband's cousin's baby girl is 3 months older than our son. Yet they're the same size. I asked if perhaps she's average for her age, and the father said yes, she's in the 20-30% range for her age. I always considered 50 to be average. But does the same rule apply to babies?

Answer 1

You're correct, being in the 50 percentile would be average, whereas 20-30% is smaller than average.  It doesn't matter if you're talking about babies or apples, 50% is average.

Answer 2

50% is average.  You know you were right, their child is scrawny.

Answer 3

If a child is in the 20th percentile for height, 20% of children are smaller than him/her and 80% of children are taller than him/her.  That's not horrible, but it is not average.

Answer 4

There is a graph with the child's age and s*x that gives the percentiles. 20-30% is small I thought. I just remember my daughter always fell within the 25% percentile for weight and the doctor was always complaining about how she needed to gain more weight.