Why Pizzerias Love You To Go Small

Friday night is pizza night! Or at least it is in my head right now!

Everyone seems to love pizza these days. Economic recession or no recession, pizzerias have never been busier. Domino’s, the world’s largest pizza chain recently opened its 777th shop in the UK, and now operates in more than 70 countries. It dwarfs all the other players including Pizza Hut chain and local favourites like the US’s Papa John’s and UK restaurants like Pizza Express and Prezzo.

Many of these pizzerias are making a lot of money too. Domino’s recently reported record sales in the UK, bringing in £14.1million during a single week in December. That’s a lot of dough! (geddit?)

But where could they be making all that money? It turns out a little-understood mathematical principle allows pizza parlours to make huge amounts of profit by down-selling us to choose smaller pizzas.

To understand, we need a little geometry lesson. Try this question:

“What’s the size difference between an 8-inch and a 16-inch pizza?”

Most people agree that the 16-inch pizza is twice as big as the 8-inch version.


Because pizzas are (more or less) circular, the surface area of a pizza increases with the square of the radius. So a 16-inch pizza is actually four times the size of an 8-incher.

My simple diagram image below shows the size relationship clearly (as well as what a tasty pizza might look like, mmmm, pizza!):


Pizzerias, of course, know this. Which is why they’ll often describe their pizzas as small, medium, and large. Or some, like Domino’s, only show how many slices of pizza you’ll get from each option but, of course, the size of a slice isn’t uniform which makes it nearly impossible for most people to do the price comparison in their heads.

All of this means that it can be very difficult for hungry diners to optimise their buying choices and many groups will default to buying several small pizzas (one for each person) rather than one large pizza for everyone to share. Assuming, that is, we can all agree on having the same pizza topping, without things descending into a heated argument!

This pricing technique is a form of reverse price decoying; effectively using the perceived fair value of a large pizza to make a smaller pizza seem like reasonable value for money. Many people know they can’t eat a whole large pizza, but a smaller pizza feels like a fair deal in comparison because we don’t appreciate how much dramatically smaller it really is.

So, next time the urge for pizza strikes, how do you get the best value for your pizza dough? Simple, do the maths! Find out the radius of each sizing option, then divide the price by the calculated surface area to find out how much each square inch is going to cost you.

Or, if that’s all a bit geeky for you, just buy the biggest pizza they sell and plan on taking the leftovers home for an unhealthy breakfast the next day. Mmmm, pizza!

Want more? Here’s some further reading: