No, even a standard 30-33cm pizza is barely enough for 1 person depending on hungry state.
A regular pizza of that size have about 2000 kcal of energy and an average male would need 2500 kcal a day (less for women), so unless you only have a single meal a day, which is unlikely, then it must be enough.
No, more in the 1000 kcal range.
Perhaps Costco pizzas - 18 inches, or about 45 cm!