Does anybody know the average size of a man foot

This is a question that will have many answers.  This is due simply to the huge variety within the species, and the differences between bloodlines, nutrition, nationality, among others.

This article pointed out a fascinating tidbit though, in the UK and US our feet are getting bigger.  How much is due to genetic changes, to nutritional changes, to weight changes, and such is just beginning to be studied.  Though governments have kept track of general measurements (if nothing else for military gear) for a very long time.

The short answer, per this article, is for the UK size 10 and stateside that’d be an 11.  

http://www.independent.co.uk/life-style/health-and-families/features/why-our-feet-are-getting-bigger-9481529.html

According to the surveys conducted in 2014 by orthopedic surgeons from American academy, the average size foot size of man is between 9-12. In US the average man’s foot size is 10.5. The taller the man is the higher his foot size.