74,476 Reasons to Get the Bigger Pizza… But Is It Really a Value?

Recently, NPR’s Planet Money team posted a great article entitled “74,476 Reasons You Should Always Get the Bigger Pizza.” In that article, the team analyzed – you guessed it – 74,476 pizza prices from pizza joints around the United States and evaluated them on cost per square inch.

Their conclusion? You get more square inches of pizza for your dollar if you buy the largest pizza available to you.

Looking at the Pizza Math

Rather than dig into their large data set of example, I chose to instead use the prices from the nearest pizza place to my house – Casey’s – as an example.

Casey’s offers three sizes of single topping pizzas. You can purchase a small (12″) single topping pizza with cheese for $8.99, a medium (14″) single topping pizza with cheese for $10.49, and a large (16″) single topping pizza with cheese for $11.99.

So, let’s do the math. What is my cost per square inch of pizza for these options?

We’re going to want to calculate the area of a circle, which is pi (3.14) times the radius of the pizza squared. The dimension of the pizza given is the diameter, and thus half of that is the radius.

So, the small pizza provides 3.14 times 6 inches times 6 inches of pizza, or 113.04 square inches of pizza.

The medium pizza provides 3.14 times 7 inches times 7 inches of pizza, or 153.86 square inches of pizza.

The large pizza provides 3.14 times 8 inches times 8 inches of pizza, or 200.96 square inches of pizza.

What’s the price per square inch?

With the small pizza, you’re paying $8.99 for 113.04 square inches of pizza, or just shy of 8 cents per square inch of pizza.

With the medium pizza, you’re paying $10.49 for 153.86 square inches of pizza, or roughly 6.8 cents per square inch of pizza.

With the large pizza, you’re paying $11.99 for 200.96 square inches of pizza, or roughly 6 cents per square inch of pizza.

Thus, per square inch, the large pizza is definitely the bargain of the three options.

Similar math rules at almost every pizza restaurant in America. If a typical “medium” pizza (usually a 14″) is less than 50% higher in price than the “small” (usually a 12″) pizza, then the “medium” is a better deal. If a typical “large” pizza (usually a 16″) is less than double the price of the “small” pizza, then the “large” is a better deal. The “large” is a better deal at almost every restaurant I checked, including some of the large chains like Dominos and Pizza Hut.

In short, you’re getting the best deal per square inch of pizza if you buy the large pizza rather than the small pizza, almost regardless of the specific variety or the specific restaurant.

The Bigger Picture: Is the ‘Cheapest’ Square Inch of Pizza Really a Value?

We’ve established that in almost every situation the bigger pizza gives you more pizza for your dollar, and it’s usually not even close. But is that really the best deal?

This whole idea came to mind the other night after I put our children to bed. I was mildly hungry and wanted a small snack, so I popped open the refrigerator to see what was in there.

One of the options, of course, was found in a large pizza box. There were a few slices left over from the pizza order our family made and so I grabbed a couple for my snack.

Now, let’s say that pizza box hadn’t been there. What would I have eaten? I probably would have grabbed something like a dill pickle or a few slices of cucumber (we often have a bowl with sliced cucumbers and onions sitting in vinegar water in the fridge during the summer).

Those snacks would have cost me very little. The cucumber slices would have been basically free; a couple of pickle spears might have cost as much as a quarter. On the other hand, using the prices listed above, those slices cost me at least $1.50.

How do I figure that? Well, let’s say I had purchased the medium pizza instead of the large one. Our local pizza place slices a medium pizza into ten slices for $10.49, while the large is sliced into twelve slices for $11.99. The slices are approximately the same size in terms of square inches, give or take a little.

(If you want some exact numbers, the medium pizza is 154 square inches, divided by 10 slices, making the slices 15.4 square inches apiece, while the large pizza is 201 square inches, divided by 12 slices, making the slices 16.75 square inches. The slices are pretty close to the same size.)

So, those two slices I ate cost me the $1.50 difference between the prices of the pizza (plus tax, of course). It was a $1.50 snack.

Here’s another way of looking at it. A medium pizza is the same as buying a small pizza plus a “snack pack” consisting of two slices of pizza for another $1.50. A large pizza is the same as buying a small pizza plus two “snack packs” consisting of two slices of pizza for $1.50 each.

The question really is whether or not that $1.50 for two more slices of pizza is worth it. That’s what you’re buying if you buy a medium instead of a small, and you’re buying two of those deals if you buy a large instead of a small.

For me, I’m not really sure it is a deal. I can have another snack that costs much less than $1.50. That snack is going to be healthier, I’ll enjoy it about as much, and it will have better long term health consequences for me.

Let’s say I use those slices to replace lunch, then. Is it still worth $1.50 to me? Again, I have other options for lunch that cost me less than $1.50. It is very common for me to have a poached egg sandwich for lunch, which basically consists of an egg (about a quarter or so) and two slices of bread (another quarter or so). I’ll often eat leftovers of other meals made at home, too.

There’s also the assumption that I’ll actually use the “extra” pizza before it goes bad. Will I eat those two or four “extra” slices beyond the small before they need to go to “leftover heaven” – also known as the trash can?

Here’s the point: The immediate assumption that the large pizza is the best “deal” because it has the lowest cost per square inch is not always the smartest conclusion. Instead, you need to look at how you’ll actually use that pizza.

Beyond the Pizza

The truth is that this pizza issue actually applies to the issue of buying any perishable food in bulk. For example, when I’m at the store, I can save on the price per apple by purchasing a bag of apples all at once, but that means I have a lot of apples. I have to consume them all with at least some rapidity or they’re going to go to waste.

Even if I do use them all, though, are the apples a great deal? If I really only need four apples and I buy 10 in a bundle because they’re cheaper per apple, that means I have six cheap apples but no real purpose for them and a limited amount of time in which to use them.

What about other restaurants? What about the idea of buying a large plate, eating only half of it, and saving the other half for a leftover meal? This is something that many people do, yet it’s not that much of a bargain. You’re paying at least a few dollars for that extra portion, plus tax, plus tip, plus there’s a risk that it doesn’t get eaten or spoils before you have the opportunity. $6 (or so) for half of your restaurant plate in a box that you have to remember to bring in out of the car or else it goes to waste? That doesn’t seem like a bargain to me.

For me, the broad solution is this: The only time I ever buy perishable foods in bulk is when I know they’ll get used.

In my family, apples definitely fall into that category as I love to eat them for a quick snack, as do my children. Buying the big platter at a restaurant? Not worth it. Buying a large pizza? Sometimes, depending on how many people are at home and what other foods we have on hand.

Too Much to Think About?

Many people shrug off this kind of thinking, viewing it as too much to bother with when it comes to buying pizza. That’s a mistake.

The point isn’t to cause a bunch of analysis to occur each time you buy pizza; rather, the point is to develop stronger frugal instincts so that you naturally know when to avoid a “bulk” purchase when it makes no sense.

Know your eating habits and those of your family members. Know what you already have on hand and what your meal plan is like. If you know those things, you can usually make a smart decision about whether it’s time to buy the large bag of apples or the large pizza instead of two individual apples or a small pizza. The better you are at making that choice, the more natural it becomes, and the more money you save and the less food you waste with every meal and snack.

Trent Hamm

Founder & Columnist

Trent Hamm founded The Simple Dollar in 2006 and still writes a daily column on personal finance. He’s the author of three books published by Simon & Schuster and Financial Times Press, has contributed to Business Insider, US News & World Report, Yahoo Finance, and Lifehacker, and his financial advice has been featured in The New York Times, TIME, Forbes, The Guardian, and elsewhere.