Pizza math in Canada: the real cost per square inch

When you look at a pizza menu, your brain naturally compares diameters. A 14-inch large pizza sounds roughly 16% bigger than a 12-inch medium. That mental shortcut is a mathematical error that costs Canadian households money on every weekend takeout order.

Pizzas are circles, not straight lines. Area scales with the square of the radius. Going from a standard 12-inch medium to a 14-inch large adds 36.1% more surface area, and at Pizza 73 it costs 26.7% more money. Every extra inch of width buys more pizza than the inch before it, and no menu prices it that way.

On almost every pizza menu in Canada, the smallest size is the most expensive way to buy dough and cheese, while the largest size delivers the cheapest calories.

The geometry of the pizza box

The mathematical formula for the area of a circle is area equals pi times radius squared:

Area = π × r² = π × (Diameter / 2)²

Because diameter is squared, every added inch of width produces substantially more food than the previous inch. An inch added to the perimeter of a 14-inch pizza contains significantly more cheese, sauce, and dough than an inch added to an 8-inch personal pie.

Here is the actual surface area for standard pizza sizes sold in Canada:

Moving from a 10-inch small to a 14-inch large does not give you 40% more food. It gives you 96.0% more food, effectively doubling your pizza for a few extra dollars.

Cost per square inch: Pizza 73 case study

To see how a menu prices that geometry, here is the Create Your Own line at Pizza 73, taken from the verified Alberta price file behind its brand page. Pizza 73 publishes a diameter against every size, which is what makes the division possible at all.

The numbers show clear price breaks:

• The 9-inch penalty: Ordering a 9-inch small costs 18.85 cents per square inch. That is almost double the cost per square inch of the 18-inch XXL (9.82 cents). You pay a 92.0% unit premium for ordering a small.
• The Medium to Large jump: Moving from a 12-inch medium ($14.99) to a 14-inch large ($18.99) costs $4.00, a 26.7% price bump. In return, you receive 40.84 extra square inches of pizza, a 36.1% increase in food. You pay less per square inch for the upgrade.
• The XXL powerhouse: An 18-inch pizza provides 254.47 square inches of food for $24.99. Two 12-inch mediums provide 226.20 square inches and cost $29.98 if purchased separately. The single 18-inch pie gives you 28.27 more square inches of food and saves you $4.99.

Sit-down casual dining: Boston Pizza case study

The same curve appears at full-service chains, from a much higher baseline. Here is the Deluxe at Boston Pizza across all four of its standard round sizes, which the chain publishes as roughly 8, 10, 13 and 15 inches.

At Boston Pizza, the 8-inch Individual pizza costs 28.82 cents per square inch. The 15-inch Large drops to 19.23 cents per square inch.

The 15-inch Large has 3.5 times the surface area of the 8-inch Individual pie (176.71 against 50.27 square inches) but costs only 2.3 times as much ($33.99 against $14.49). If two people at a table each order an Individual, they pay $28.98 for 100.54 square inches. Splitting one 13-inch Medium costs $28.79, nineteen cents less, and puts 132.73 square inches on the table: 32% more pizza for the same money.

Boston Pizza's create-your-own line is cheaper again, and it is where the best single step on the menu sits.

Look at the medium-to-large step on its own rather than at the averages. Going from the 13-inch to the 15-inch costs $3.50 and adds 43.98 square inches, a marginal rate of 8.0 cents per square inch — barely half the 14.71 cents the large pie averages overall, and a third of what the Individual costs. It is the best-value upgrade anywhere on the Boston Pizza menu.

The crust edge ratio: why big pizzas have more toppings

There is a second hidden factor that makes smaller pizzas even worse value: the crust-to-topping ratio.

The crust border around the edge of a pizza is approximately one inch wide regardless of whether the pizza is an 8-inch personal pan or an 18-inch party size. This plain dough rim takes up a massive proportion of a small pizza, but only a modest slice of a large one.

On an 8-inch pizza with a one-inch crust edge, the topping circle in the centre has a 6-inch diameter. That means only 28.27 square inches of the pizza actually have cheese and sauce, while 22.00 square inches (43.8% of the pizza) are bare crust.

On a 14-inch pizza with the same one-inch crust edge, the topping circle is 12 inches across. That leaves 113.10 square inches covered in toppings, while the crust rim takes up 40.84 square inches (only 26.5% of the total pie).

When you buy a large pizza, you are not just getting more square inches per dollar. You are getting a substantially higher percentage of cheese, meat, and sauce rather than plain bread.

One large against two mediums

The Friday-night question is whether to order two mediums with different toppings or one big pizza split down the middle. With Pizza 73's Create Your Own prices, the arithmetic is not close.

One 18-inch XXL beats two 12-inch mediums on both counts at once: 28.27 more square inches of pizza for $4.99 less money. That is the rare case where there is nothing to trade off, and the only reason to take the two mediums instead is wanting two genuinely different pizzas rather than a split one.

The same holds a step down. A 14-inch large at $18.99 gives 153.94 square inches against 127.24 for two 9-inch smalls at $23.98, so the single large is more pizza for five dollars less.

If you do want two toppings, ask whether the counter will split the larger pie half and half. Where it will, the geometry is free money.

Frequently asked questions

Is one 18-inch pizza bigger than two 12-inch pizzas?

Yes. An 18-inch pizza has an area of 254.47 square inches. Two 12-inch pizzas have a combined area of 226.20 square inches. The single 18-inch pizza gives you 28.27 square inches more food, equal to roughly two extra slices of a medium pizza.

What is the cheapest pizza size per square inch?

The largest size on the menu, every time. At Pizza 73 the 18-inch XXL Create Your Own works out to 9.82 cents per square inch against 18.85 for the 9-inch small. At Boston Pizza the 15-inch create-your-own is 14.71 cents against 23.85 for the 8-inch Individual. Cost per square inch falls steadily as diameter grows, because the dough handling, the box and the oven time cost the restaurant roughly the same at any size.

Why do small pizzas cost so much per square inch?

Fixed preparation costs. The cook still needs to stretch the dough, assemble the box, and run the oven whether the pizza is 8 inches or 14 inches. Restaurants apply a price floor on small pizzas to cover packaging, labor, and overhead.

Does a square pan pizza give more food than a round pizza?

Yes. A 12-by-12 inch square pizza has 144 square inches of surface area. A 12-inch round pizza has only 113.10 square inches. The square shape provides 27.3% more surface area for the same nominal width.

How many people does a 14-inch pizza feed?

A 14-inch large is 153.94 square inches, usually cut into 8 or 10 slices, which is a comfortable meal for three ordinary appetites or two large ones. For four or more, an 18-inch XXL gives you 254.47 square inches — 65% more pizza than the 14-inch for $6.00 more at Pizza 73.

Are two-pizza deals cheaper than buying one big one?

Do the division before assuming so. Two 12-inch Pizza 73 Create Your Own pizzas cost $29.98 for 226.20 square inches. A single 18-inch XXL costs $24.99 for 254.47. Unless a promotional bundle is priced below $24.99, the one big pizza wins on both food and money. A two-for-one only helps if the pair costs less than the largest single pie on the menu.

Methodology and disclaimer

Areas use the standard circular formula π × r², applied to the diameters each chain publishes for its own sizes. Prices come from the verified menu files behind this site's Pizza 73 (Alberta pricing) and Boston Pizza (national menu) pages, recorded August 2026, and exclude provincial sales taxes and delivery fees. The one-inch crust border used in the topping-ratio section is a working assumption about commercial pizza-making, not a figure either chain publishes; actual crust width varies by dough handling and oven spring.

Froqel is an independent price guide. We are not affiliated with, endorsed by, or sponsored by Pizza 73, Boston Pizza, or any restaurant chain named here. All trademarks belong to their respective owners.