My wife and I have wondered about my son's height for some time. Since the day he was born he's been in either the 90th percentile or 95th percentile for height and weight. He just turned 12 last month and the official numbers from the doctors office put him a 5'4" tall and 122lbs. That put him in the 95th percentile for height and the 90th percentile for weight.
My wife is just over 5' tall and I'm just under 5'9" tall. My wifes mother, father, and brother are all shorter than I am. I am however the short man in my family. My younger brother is about 6' tall. My father was 6'2" tall. I say "was" because he's almost 69 years old and appears to be shrinking with old age.
One of my dad's brothers was 6'7" tall.
When we look at those height calculators we usually get two different results. The ones that figure his height based on mine and my wifes height say he'll only reach 5'7" tall. That's hard for me to believe since he's already 5'4" tall. The height calculators that don't ask for mom and dads height, ask for his birthdate, current height, and his current weight. The results from those predict he'll be just over 6'2" tall and around 200lbs by the time he's 18 years old. They also say he could be as short as 6'1" and as tall as 6'4". All of that is dependant on stress, nutrition, and disease.
I'll feel much more comfortable about those predictions once he's passed me by. My younger brother was 5'8" as a 12 year old and only grew to 6'. Hopefully my 5'4" 12 year old has more than 4 inches of growth left in him. Otherwise he'll be shorter than dad.