Little and large: 6ft 4" Michael Phelps towers over 4ft 8" Simone Biles in photo that shows the height difference between America's biggest Olympic stars

Michael Phelps (left and top right) is 31 years old, stands at 6ft 4" tall and has won 28 Olympic medals during his long swimming career. 


Simone Biles (left and bottom right) is a newbie to the Games at just 19, is 4ft 8" and won her third gold medal Sunday night. He was in rehab for substance abuse last year and she was put up for adoption when she was only six year's old because her mother's drinking and drug use. But despite their vastly different back stories and physical attributes - demonstrated in a hilarious photo of Phelps towering over Biles which she posted on Twitter -  they are now America's biggest Olympic stars at opposite ends of their respective careers.