
I figured out exactly how tall Greg is
figured out how tall Greg is. Explanation below:
Basically, in Big Shot, it shows him next to a basketball hoop. I measured the basketball hoop to the ground level in the image and figured out that in the image, it is 43.54 times smaller than real life (if I remember correctly). Then I found an image where Greg is standing up straight (he is always slouching) and it was the exact same proportions as the other one, as the head an arm length were the same. This allowed me to easily multiply his image height by 43.54 and convert it to feet.
Greg Heffley is 5 feet 0 inches tall in the Big Shot book.