A useful starting point is about 250 g (8.8 oz) of dough for one 12-inch round pizza. Ooni recommends 250 g dough balls for its 12-inch pizzas. The exact amount depends on how thin or thick you want the crust and how much rim you leave.
For a thinner crust, you may want to stretch the dough farther; a thicker or pan-style crust needs more dough. Treat 250 g as a recipe example, not a universal standard. See Ooni’s pizza dough preparation guide.
For a thin-crust 12-inch pizza, about 4 oz (113 g) of grated cheese is a practical example. King Arthur Baking says 1 cup, or 4 oz, is enough for a 12-inch thin-crust pizza. A thicker crust, extra-cheese style, or different cheese may call for more.
Use the recipe amount as a starting point and spread the cheese evenly. See King Arthur Baking’s thin-crust pizza tips.
Dough and cheese are recipe quantities, not fixed measurements for every 12-inch pizza. Thin crust, pan pizza, sauce moisture, cheese type, toppings, and the size of the outer crust all affect the amount. If you are comparing the pizza itself by diameter and area, see our 12-inch pizza size guide.