Pizza Rule

If you let the radius be Z, then you can find the area of a pizza with a simple formula:

Pi * Z * Z = A

I love this
I wish I could award you with fake Internet points.

I once taught private lessons in math on calculating the area of a circle and I wanted to show the students how much cheaper per area a larger pizza is. So we of course got the diameters of pizzas from their favorite restaurant and started calculating. Then we found out that the normal sized pizza was actually the cheapest per area. It wasn‘t quite what we expected, but a very good math lesson for the attendees nonetheless: The owner lost money, because they were bad at maths.

You didn't consider the crust ratio, did you?
The crust tends to be a consistent width, so it represents a greater portion of a smaller pizza, shrinking the bit most people are there for.
...but hey, if you love the crust just as much, more power to ya!
- Keeping the total pizza volume fixed, many smaller pizzas also means more boxes.
- That's why you order thin crust and get those toppings out to the edge
I have an app for that, put the price and diameter of different pizzas and it says what's the best one price wise.
- What's the app?
- Care to share with the class?
Did you take into account that the crust takes away area from the "filling"? Because me and my husband also once did the math (not sure if we were frugal, bored or broke) and it all came down on whether you eat/enjoy the crust or not
- Crust is part of the pizza. That's what dipping sauces are for.

But the 2 12” pizzas have more crust, so it depends what you prefer.

I’m wholly in the pizza centre and fuck the crust camp. But for those who like the crust…

You're meant to eat the crust, not fuck it, that might be where you're going wrong
- You're meant to eat the crust, not fuck it
  Really? Guess now I know why everyone has been looking at me funny after the company pizza party 🤔
- Then why did they invent stuffed crust?
I mean I like crust but who's out here looking for a higher crust ratio?
Shit man, I'm a crust guy but hate paying more for less...
You sort of ruined my life now.
Merry x-mas you bastard

ok but that picture is clearly one 18" pizza vs two 18" pizzas that have been hit by a shrink ray, meaning the two on the right have twice as much nutrition as the one on the left.

Ah but it's mini-nutrition now, so you have to shrink yourself in order for your body to be able to process it
Your math is wrong.
Each calorie on the shrunken pizza is only a half-calorie now.

On this episode of: The internet goes to primary school

What's an inch?

- So convenient.
About the length of the last segment of your thumb.
Not enough
- dang
1in = 2.54cm
^beep ^boop ^I’m ^not ^a ^bot
About 1/5th the size of the average American penis

It's 6.99 for a 12in pizza with 2 toppings but $20 for a 18in with no toppings. I don't even know why it's a option.

You can compare areas with just r^2 you don't even need pi. So the math is easy.

A pizza is larger than two of another just before it hits 1.5 times the radius (sqrt 2 times, to be exact, about 1.41). So if the radius is 1.5 times bigger, like in the OP, you always know it's more than twice the area.

Depends on the price difference.
https://www.omnicalculator.com/food/pizza-comparison
Domino's is hardly considered pizza by most but it's $7 for a 12in. A 18in is $20. That's almost 3 pizzas. And the 12in has 2 toppings. The 18in has 0 toppings.
- Dominos actually got better. It's not amazing but they took it on the chin a few years back and were like, "our pizza sucks. We need to do better" and they actually improved it quite a bit.
- They also have carryout one topping 14" pizzas for $8 in my area, which is an even better deal than $7 for 12".
The math only really works for 18+ inch pizzas though. The pizza places around me don't even offer 18 inch pizzas. 14" large or 16" XL are the highest they go. In that case at most places near me, two twelves is often cheaper per square inch and does have more area than one 14" or 16". Especially since Domino's usually has coupons for two 12s that make it significantly cheaper than 1 L or XL.
- Pizza place that just opened up down the street from me only offers one size:
  18 inches.
  The other option is to purchase by the slice.

Pizza π

The volume of a pizza with a radius of "z" and a height of "a" is πz²a, or pizza
- Very nice :)

you can fit more pineapples on the one 18 inch pizza

The most worthwhile comparison is of the surface area, excluding crust. Crust quotient must be disregarded.

Not if you like crust

I saw this exact thing in a pizza shop an hour ago. What the actual hell

I figured this out pretty quick when I was 16 trying to calculate the optimal pizza per $ order when I first started getting allowance

Importantly, it also has a different crust-to-center ratio, which - depending on your taste - could be a reason to go for less pizza.

given a choice, i usually go with larger pizzas for crispy thin crust (also cut those in squares); and smaller ones for 'deep dish' or pan, where there isn't really an outside 'crust'.

How come I am able to eat an entire 18'' pizza to my face but get full of I try eating two 12'' pies? 🤨

2 12" pizzas are 112.5% the surface area of as single 18" pizza.

At least you didn't measure the pizzas with your feet.

fun fact: to find the actual diameter of the pizza that would larger by a factor of x its (D/2)*2√x

good luck finding a place that offers irrational size pizza though

yeah, but
C_1 = pi * d = 3,14 * 18 = 56,52
C_2 = pi * d * 2 = 3,14 * 12 * 2 = 75,36

so the smaller ones have 50% more crust and are therefor more delicious.

This is not righteous.

9 is more than 2 times 4

But… it’s twice as many slices!

Well IRL that wouldn't be the case since the pepperoni is the same size on a 12 vs 18 inch, therefore more pepperoni slices on the 18 inch due to the larger area
But each slice of salami on the left has more than twice as much salami as each slice of salami on the right.
There's no cheating math.

I found myself making a similar calculation recently - I have a project car, and when I dragged it out of a field and hacked the vegetation out of the engine compartment, there was a 40mm motorcycle carburetor mounted to an adapter mounted to the intake. The carburetor even had a Harley-Davidson logo embossed in it.

I wanted to put a two-barrel Weber carb on it, which had a 36 mm and a 32 mm throttle plate. The 40 mm motorcycle carb had an area of 1256 mm², while the combined area for the Weber was more like 1820 mm².

Is this a prank