The formula
ball = area × thickness factor · area = π × radius²
Where it comes from
The weight of a dough ball comes from the area, not the diameter, because dough stretches in two dimensions while the thickness stays the same. So a forty-centimetre pizza does not take twice the dough of a twenty: it takes four times. The thickness factor is grams per square centimetre, and it is the number a pizzeria uses to define its style: 0.37 for a Neapolitan with a puffy rim and thin base, 0.7 for a deep pan.
How to work it out by hand
- Work out the area of the pizza: pi times the radius squared
- Multiply by the thickness factor of the style you want
- Multiply by the number of pizzas for the total dough
- Split that dough by baker's percentage, where the flour is 100 %
What is worth knowing
The same arithmetic explains why a family pizza should not cost twice a personal one: it costs four times as much in dough and toppings. On hydration, 60 to 65 % is manageable by hand; above 70 the dough sticks and needs folding technique. And fresh yeast at 0.3 % is for a twenty-four-hour cold ferment, which is where the flavour comes from: to make it in two hours at room temperature you would need five or six times as much.