Definitely not typical in all of europe at least. Dominos here offers 25, 28, or 32cm diameter, and most other pizzas I’ve had, fast food or not, have always been in that range as well (though I can only speak for germany and the netherlands, haven’t had fast food pizza elsewhere and I don’t even really remember how big the pizza I had in italy 10 years ago was). 40cm is family size here (one local place used to have 50cm family pizzas, which are definitely 2 or even 1 slice per person territory).
Definitely not typical in all of europe at least. Dominos here offers 25, 28, or 32cm diameter, and most other pizzas I’ve had, fast food or not, have always been in that range as well (though I can only speak for germany and the netherlands, haven’t had fast food pizza elsewhere and I don’t even really remember how big the pizza I had in italy 10 years ago was). 40cm is family size here (one local place used to have 50cm family pizzas, which are definitely 2 or even 1 slice per person territory).