Question

What is the size of the tallest person

Answer 1

The size of the tallest person is 8'11

Answer 2

Assuming that you are referring to the tallest person that ever lived (instead of tallest living person), he was 2.72 m tall or 8ft 11.1 in. (Robert Wadlow)

The tallest person living today is named Sultan Kosen and he is 8ft 3in