it is the size of your foot divided by 2
pro size
They use a official youth size football that you can find at any walmart or sporting good store
Official
Regular size
So football players know where to go
college football size vs. high school football size
high school use adult size football. And most high school leagues use a collage style ball instead of a pro style
For under 14 Gaelic Football, you use a full size pitch and goals, with a size 4 football being used...
there are many sizes ranging from the lesser used size 2 to size 6 proffesionals use size 5
The size of a football used in high school is 11.5 inches long. It has a diameter of 6.7 inches around.
A college size football is about the same as highschool size football Pro is a size up from college
I think that a paramecium looks like an American football or a rugby ball but I do not know the size