Calculate The Surface Area Of Pizza To Locate The Best Deal?

If you’ve ever stood at the grocery store trying to figure out if it was a better deal to buy two smaller pizzas or one larger pizza, this story is for you. What happens when a personal finance blogger gets offered two 8″ pizzas instead of one 12″? Geometry! From The Binary Dollar:

After doing some quick mental math (area of a circle = pi*radius

. Two 8

pizzas = 2*pi*(4)

= 32*pi square inches, One 12

pizza = pi*(6)

= 36*pi square inches), I told her we’d be missing out on over 12 square inches of pizza, so we’d rather just have the one 12

pizza. She complied, and as a nice bonus (probably because she was impressed by my quick geometry skills), she let us have the extra 8

pizza anyways. Score one for geometry!

We doubt the part about the waitress being impressed by geometry skills, but the rest of it sounds about right. —MEGHANN MARCO

Geometry Saved Me Money [Binary Dollar]
(Photo: Dustin P. Smith)


Edit Your Comment

  1. yasth says:

    Ummm, taking into account the crust comes to mind as a good idea, though in this case it probably wouldn’t matter.

    Also, more food is not the ideal situation for most people.

  2. acambras says:

    They say the geeks shall inherit the earth.

  3. MostNutsEver says:

    You know, like nunchuck skills, bowhunting skills, geometry skills… Waitresses only give extra 8″ pizzas to customers who have great skills.

  4. Phishy says:

    Too bad this doesn’t ake into count the quality/quantity of toppings. Not to mention the hearty goodness of a deep dish!

  5. Bye says:

    Pizza pie 4 R squares!

  6. Why does it look like the sauce is on top of the cheese in the photo?

    @Rey: Ha!

  7. junkmail says:

    @Rectilinear Propagation: That is the magic of Giordano’s Pizza. BEST PIZZA EVAR. (great pic choice, btw)

  8. Toof_75_75 says:

    That picture makes me REALLY hungry!

    And the reason is because that’s how some places (areas) make their pizza…Strange but true!

  9. Meg Marco says:

    It’s Chicago pizza! It’s not strange!

  10. getjustin says:

    Um, how about I pick my pizza based on how tasty it is?

  11. mopar_man says:


    I have to agree. I had it for the rest time in December. Fantastic pizza. You can also make several meals out of that one huge pizza.

  12. joeblevins says:

    Thin crust rules!!!

  13. Trai_Dep says:

    Getting a free pizza because of geometry skills is about as likely as hearing, “Take my virginity, Algebra Boy!”

    Sure nice thought to keep the boys focused and in school. But. No.

  14. MeOhMy says:

    @getjustin: It’s about choosing between 2 8″ or 1 12″ pizza at a single location, though. Unless you have reason to believe that the 8″ and 12″ pizzas don’t actually taste the same, it becomes purely a value call.

  15. gwong says:

    Better living through mathematics!

  16. ElizabethD says:


    What you said about the crust ratio.

    Two smaller pizzas = higher percentage of crust area to flat-part-with-all-the-goodies-on-it. Unless you love eating the crust more than the toppings, it would be better to get one larger pie with half one topping, half the other.

  17. gridman says:

    Kudos for spotting that. Most people seem to mistakenly believe a 16″ pizza is twice the size of an 8″ pizza.

    I’ve been reviewing pizzas for several years, and have been applying the square inch measure in an effort to fairly assess the relative expensiveness of restaurants. That, of course, cannot account for the relative quality (read: taste) of the restaurants, but there’s also a problem with using that technique for choosing between two pizzas in the same restaurants.

    The square area jumps dramatically with each 2″ increment (8″=50sq”, 10″=79sq”, 12″=113sq”, 14″=154sq”, 16″=201sq” (all approx)) leading to a 16″ pizza being over 4 times the area of a single 8″ pizza.

    Almost certainly, you will never find a restaurant that charges 4 times as much for the 16″ than the 8″, so the larger pizzas are almost always the “better deal.”

    The problem is there’s also a corresponding drop in the doneness of the pizza at most pizzerias (not all, of course.)

    Four 8″ pizzas will almost certainly be better cooked than one 16″ pizza. It’s not a popular notion with the bean counters or the people who think there’s fun to be had sharing a pizza, but if you’re in it for the flavor, go with the small.

  18. notallcompaniesarebad says:

    I hope they saved all their extra pizza for another meal — otherwise they should have factored in the additional health care costs…

  19. mac-phisto says:

    personally, i think the best deal is calculated based on personal tastes that cannot be figured with geometry equations. i would much rather spend $8 on a few slices of grandmas from calamari’s in bay ridge than on a pie from domino’s. you’re definitely getting more pizza taking your bucks to the dots, but the satisfaction cannot compare.

    & on that note, i think i will be leaving work early for a little trip to brooklyn.

  20. thrillhouse says:


    yes, and in the case of Chicago style pizza, you’ve gotta take depth into consideration – this is no two-dimensional object! There’s pizza, and then there’s Chicago pizza.

    Pardon my drool…..,,,,

  21. Tallanvor says:

    You have no idea how much that picture makes me miss Chicago! And how hungry it makes me…

  22. jamier says:

    I worked at a pizza place for 5 years and this was very difficult for my customers to understand when they wanted to know what sizes were the best deal (which happened very often!!). You don’t need to worry about anything but the radius squared.

    One regular didn’t trust my math so he actually brought his laptop in one night and made an Excel spreadsheet to figure out the surface areas. All it takes is about 5 seconds of 8th grade math in your head!!

  23. orig_club_soda says:

    Only works if quality was equal to quantity. Personally I go after taste.

  24. homerjay says:

    MMMmmm……. Pi……….

  25. Squeezer99 says:

    wouldn’t it just be easier to compare them by weight?

  26. mopar_man says:


    Why? Because you have to eat more of it to get full? I’ll take a 1″ thick deep dish pizza over some skinny-ass thin crust pizza any day.


    If you live in Florida, you can still get it:

    You can also mail-order it but I’m not sure how well that works:

  27. jchennav says:

    Stick with a medium for Chicago stuffed pizza. The large stuffed pizzas tend to be undercooked in the middle.

  28. tubgnome says:

    I second the “Why not just compare them by weight?”. Surface area is less accurate and not even printed on the packaging.

  29. w00t for Giordano’s!

  30. Nick says:

    @tubgnome et al:
    I don’t think they’re talking about frozen pizzas (which you can easily compare by weight), rather, this is purely a “You’re at a restaurant and want to know how the different sizes of the same style of pizza compare price-wise.”

  31. FreakyStyley says:

    @mopar_man: Thanks! I was just wondering if I could order Giordano’s to be sent to me.

  32. The Bigger Unit says:

    @Squeezer99: Are you going to ask the person selling you the pizza to go to the back, weigh two 8″ pizzas vs. one 12″ pizza, subtract the difference, and tell them to come back and give you the results?

  33. lpranal says:

    I have nothing to add to this, except that giordino’s is the best slice of pie outside of NYC

    oh, and that it seemed insanely cheap for what you get

  34. junkmail says:

    @mopar_man: Definitely, I can usually do a piece and a half, then the rest is taken home for midnight munchies. It amazes me how they cram such an extraordinary amount of food into such a small space… I’m pretty sure they’re violating a few laws of physics somewhere…

    Thanks for the link, btw, I didn’t know you could have it shipped. Though it sucks that the selection is so limited. I guess another road trip is in order… w00t!!11

    @thrillhouse: Agreed. :D

  35. junkmail says:

    FYI, Just placed an order for two pies. Total was $73 with next day shipping, (yikes!!!1). They should arrive Thursday, so I’ll let you guys know how it goes, (if anyone cares).

  36. Tallanvor says:

    @mopar_man: Alas, I’m in London, so no pizza shipments for me!

    For anyone who hasn’t had real Chicago style deep dish, it’s worth the price they’re charging!

  37. zolielo says:

    What about cost to generate a cost per inch? I have not do such cost per inch of pizza cals but have done cost per oz… Sometime there is a disproportionate cost per unit.

  38. acceptablerisk says:

    For those ever in the Champaign/Urbana area, stop by the Papa Del’s Pizza. Not too unlike the Giordano’s but I prefer them, personally.

  39. palaste says:

    News flash: Adult remembers basic grade-school geometry. Film at 11.

  40. cakesy says:

    Ha, that reminds me of a funny story. The other day I was at the shop and the had two different sizes of a product at different prices, so I used rudimentary maths skills I learnt in Primary school to calculate which had the better deal, and I bought that one.

    Seriously, I thought that everybody had done this. The only advantage would be if you want more toppings.

  41. fupachalupa says:

    Honestly, my stomach doesnt care how much surface area is in a pizza. I would have to go by weight of the product. Give me a sphere of pizza that weighs more and will cook right and I will be happy.

  42. Grrrrrrr, now with two buns made of bacon. says:

    So in other words, this is the formula for…*drumroll*…

    Pizza Pi?

    Thank you, thank you, I’ll be here for the next 5 minutes.

  43. guroth says:

    A Round Table Pizza 12″ has 8oz of cheese and an 8″ has 5.5oz of cheese. So even though two 8″ will have less surface area you are going to get more cheese than the single 12″, and the same is probably true for all the other toppings. The toppings are obviously the more valuable portion of the pizza, and thus although the customer in question is good at geometry, he sucks at life.

  44. junkmail says:

    If anyone still cares about this old-ass article… the pizza freakin ROCKED. Stick with the cheese, though, the spinach was a little heavy-handed for my tastes.