One day last year, an engineer and I went to a pizza place for lunch. The engineer told me he wasn't very hungry, but he said he was going to get the 12-inch medium instead of the 8-inch small — because the medium was more than twice as big as the small, and it cost only a little bit more. This sort of blew my mind.
So I went big on the pizza-value question. The graph below is based on 74,476 prices from 3,678 pizza places around the country. To see how the price of pizzas changes with size — and how much more pizza you get when you get a large — drag the slider at the bottom the graph.
The math of why bigger pizzas are such a good deal is simple: A pizza is a circle, and the area of a circle increases with the square of the radius.
So, for example, a 16-inch pizza is actually four times as big as an 8-inch pizza.
And when you look at thousands of pizza prices from around the U.S., you see that you almost always get a much, much better deal when you buy a bigger pizza.