Pizza Party Calculator
How many pizzas to order from the guests and the slices each will eat, and which of two sizes is the better buy by price per square inch or centimetre.
Slices wanted and pizzas to order (rounded up, with the spare slices), and for two sizes their areas, area per slice, price per unit area and which is the better value — at the slice counts you decide.
Example: 8 adults at 3 slices and 4 children at 2 want 32 slices — 4 pizzas of 8; a 16 in at 18.99 costs 0.094 per in² against 0.115 for a 12 in at 12.99, with 1.78× the pizza.
Slices add up,
area squares up.
How the order is counted, why a pizza’s size goes with the square of its diameter, how two sizes are compared fairly, and what the page does not guess.
The order
Slices wanted are adults × slices each plus children × slices each; pizzas are that over the slices a pizza is cut into, rounded up. Both slice counts are yours — three slices an adult and two a child are common starting points, a hungry crowd more — and the spare slices show how much the rounding added.
Size and value
Area is πd²/4, so a 16 in pizza is not a third bigger than a 12 in but 78 % bigger. Price divided by area is the fair comparison, and the page names the better value of two offers. Area per slice tells you whether "8 slices" of a small pizza are small slices.
What the number does not settle
Appetite, toppings, crust thickness and leftovers are not predicted; a deep-dish slice feeds more than a thin one of the same area. Inputs stay in your browser; the same anonymous usage counts as the rest of the site apply.