What size is a full sheet cake pan?

Typically a full sheet cake pan is 18"x24" and will serve 108 2"x2"servings. This size pan, however, will not fit in a standard oven so manufacturers have created other sizes that are still referred to as "full-sheet." Though the math really doesn't work out:

1/4 sheet pans are 9"x13"

1/2 sheet pans are 12"x 18"

Full sheet pans are 18"x24"