One 18″ Pizza Is More Pizza Than Two 12″ Pizzas, Math Shows Us Why – Primer Tackling the Serious Issues

Pause for a moment and consider a question that really matters: what size pizza should you order?

If you’ve found your way to Primer, it’s likely you're the kind of savvy consumer who likes a good deal, and hates getting taken for a ride. So here’s the thing:

All those two-medium-pizza deals you always see and probably buy, thinking “two for one? That’s got to be a better deal!” Scam city.

Archimedes, mathematicians, and 7th grade geometry teachers have known the truth about pizza sizes for years, but it’s time to spread the message to the masses:

A large pizza is almost always a better deal than two mediums. Because it’s simply more pizza. Why? Math.

It has to do with the mathematical nature of the area of circles. When you increase the width of your pizza it actually adds to the total size of your pie exponentially. For example, a 16-inch large might seem twice as big as an 8 inch small but it’s actually four times as much pizza.

Skeptical about the math? Let's compare a single large 18” pizza to that 2 medium 12” deal we mentioned earlier:

As you recall, the formula for the area of the circle is πr², with r being the radius of the pizza (i.e., half the diameter, which is its size).

Area of two 12” pizzas:

12/2 = 6   6×6=36   36xπ = 113.1 in² x 2 = 226.2 in²

Area of one 18” pizza:

18/2=9   9×9=81   81xπ = 254.5 in²

The numbers don’t lie.

But what about crust, you might ask? Crust ratio is generally the same across pizza sizes, so the 12″ pizzas have less non-crust pizza than the 18″.

A study of nearly 4,000 pizzerias confirms it: if you buy based on price-per-square-inch, the large is always a better deal.