We can predict the adult height of a child either by doubling their stature at the age of two (isn’t it incredible that we grow to half our full adult height within our first two years?) or by calculating what is called MPH (mid-parental height). For a boy, in centimetres, the equation is: father’s height + mother’s height + 13 ÷ 2; for a girl: father’s height – 13 + mother’s height ÷ 2.