Did you know arm span ( or reach ) is approximately equal to height?
How to calculate arm span
We tested this out against a wall using chalk to mark reach and then standing next to the wall to see if it matched height. You should measure from finger tip to finger tip and not have a flat hand as in this photo.
We found my 6 year old’s arm span did equal his height and my 4 year old was a little taller than hers.
Ape index is the ratio of arm span relative to their height. So my little boy had an ape index of 1.
A arm span greater than height is thought to be advantageous in some sports such as swimming, as longer arms may give greater propulsion. A shorter arm span is useful for weight lifters as they don’t have to lift the weight as high.
Can you work out your Ape Index?
More human body science ideas
Can you work out how many feet tall you are too?
Or try some of these great preschool science ideas.