I don't think the major pizza chain restaurants in America serve pizza that big anymore. You could find them in local pizza joints but they're rare. Also, kson is half right about about the size differences, except they Japan's large is more like America's medium.
Asian's large is more or less America's medium, and that doesn't apply only to pizzas.
Food portions in general follow this trend, unless you happen upon a gourmet establishment who understands that when you order a large, you want the large serving.
in Brazil, meals are generally designed to serve a X number of people for example, and a 2 people meal can normally serve 3 people VERY and leave you with leftovers. Pizza in here is measured by diameter in cm most mediums will be 35 to 45cm, family sizes are generally upwards 60cm, some can 70cm or more.
This size... In Japan, this is L-size. But in America, this is S-size.This is $40!This is Kids Size!!This is USA's L-Size!But in Japan, sushi is inexpensive and delicious! Japan is the best!Futon Cover