Pizza Comparison Calculator

Compare two pizzas by price per square inch to find the better value.

Everyday $ per sq in Auto winner
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Which pizza is the better deal?

Price per square inch · area ratio · savings %

Instructions — Pizza Comparison Calculator

1

Enter both pizzas

For each pizza, type the diameter and the price. Use inches or centimeters — the units toggle changes both fields at once. Diameters in US menus are usually inches; in Europe they are usually centimeters.

2

Pick a currency

Defaults to US dollars. Switch to euros, pounds, or Canadian dollars as needed. The currency only affects the display — the math is identical, since the calculator computes price per unit of area, not absolute price.

3

Read the verdict

The headline names the winner. The grid shows both areas, both prices per square inch (or per square centimeter), and the size and price ratios so you can see exactly how much extra pizza you get and how much extra you pay.

Squared, not linear: a 14″ pizza has 36% more pizza than a 12″, not 17%. Area grows with the square of the diameter, so each extra inch of width adds a surprising amount of pizza.
Watch the toppings: the calculator compares dough surface. A plain cheese pizza and a loaded supreme of the same size aren't the same cost to make. Compare like-for-like configurations when you can.

Formulas

Pizzas are circles. Cost-per-pizza is meaningless without knowing area, and area depends on the square of the diameter.

Area of a circular pizza
$$ A = \pi r^2 = \frac{\pi d^2}{4} $$
Where d is the diameter and r = d/2 is the radius. The factor π ≈ 3.14159. A 12-inch pizza has area π × 36 ≈ 113.1 sq in.
Price per unit of area
$$ p = \frac{P}{A} $$
P is the price, A is the area. This is the unit price — the same concept supermarkets use for ounces and pounds, but here for square inches of crust.
Savings percentage
$$ \text{savings\%} = \left( \frac{p_\text{worse} - p_\text{better}}{p_\text{worse}} \right) \times 100 $$
How much you save per square inch by choosing the cheaper pizza, as a percentage of the more expensive option. A 20% better deal means you pay 20% less for the same amount of pizza.
Size ratio between two pizzas
$$ \frac{A_2}{A_1} = \left( \frac{d_2}{d_1} \right)^2 $$
The pizza-area ratio is the square of the diameter ratio. A 16″ vs 12″ pizza: (16/12)² = 1.78. The 16-inch is 78% bigger.
Centimeters to inches
$$ d_\text{in} = \frac{d_\text{cm}}{2.54} $$
Used when you mix units. The calculator handles this automatically when you switch the toggle.
When two pizzas tie
$$ \frac{P_1}{d_1^2} = \frac{P_2}{d_2^2} $$
The two pizzas are equal value when price scales with diameter squared. Doubling diameter for 4× the price keeps the per-square-inch cost constant.

Reference

Standard pizza diameters and areas
LabelDiameterAreaSlices (typical 8-cut)
Personal8 in50.3 sq in4–6
Small10 in78.5 sq in6
Medium12 in113.1 sq in8
Large14 in153.9 sq in8–10
Extra Large16 in201.1 sq in10–12
XXL18 in254.5 sq in12–14
Party20 in314.2 sq in14–16

How much pizza is gained by going up a size?

Each extra inch of diameter adds more area than the last, because area grows with the square.

Size step
Going upExtra area
10″ → 12″+44%
12″ → 14″+36%
14″ → 16″+31%
16″ → 18″+27%
18″ → 20″+23%
Two-pizza math
CombinationTotal area
2 × 10″157.1 sq in
1 × 14″153.9 sq in
2 × 12″226.2 sq in
1 × 18″254.5 sq in
2 × 14″307.9 sq in
1 × 20″314.2 sq in

Two 12-inch pizzas (226 sq in) give roughly the same amount as one 18-inch (255 sq in). One 20-inch beats two 14-inch by only 2%, but is usually cheaper than ordering two.

Article — Pizza Comparison Calculator

Pizza Comparison Calculator

A pizza comparison ranks two pizzas by price per square inch. The math is simple: area = π × (diameter / 2)², then divide the price by the area. The pizza with the lower price per square inch is the better value, regardless of which one is cheaper on the menu.

The reason two pizzas are hard to compare by eye is that pizza area grows with the square of the diameter, not the diameter itself. A 14-inch pizza is 36% bigger than a 12-inch, not 17%. A 16-inch is about 1.8× a 12-inch. The price tag rarely scales with that math, which is exactly why some sizes are quietly much better deals.

What is a pizza comparison?

A pizza comparison normalizes the cost of two pizzas to a common unit? the square inch of crust? so you can pick the better value. Supermarkets do the same thing for milk in ounces and cheese in pounds. Pizzerias do not advertise per-square-inch prices, so the comparison falls to the buyer.

The output is a winner and a savings percentage. A 20% better deal means you pay 20% less per square inch by choosing the cheaper option, not that the absolute price is 20% lower. For a couple sharing one pizza, the savings rarely change the meal. For a family ordering several or a party ordering a dozen, the difference adds up to real money.

Pizza comparison by price per square inch

Price per square inch is the right metric because it accounts for both factors that matter? how much pizza you get and how much you pay. Two pizzas tied on per-square-inch price are equal value, even if their headline prices are wildly different. A $9 12-inch and a $16 16-inch both land at about $0.080 per square inch.

  • Below $0.07/sq in — very cheap; usually a coupon or low-end chain.
  • $0.07–$0.10/sq in — standard US chain pricing (Domino's, Pizza Hut, Papa John's).
  • $0.10–$0.15/sq in — typical local pizzeria, mid-range quality.
  • $0.15–$0.25/sq in — gourmet, wood-fired, specialty pies.
  • Over $0.25/sq in — tourist trap, premium ingredients, or both.

The pizza area formula

Every pizza is (close enough to) a circle. The area of a circle is π r², where r is the radius. Pizza menus list the diameter, so the working formula is:

Pizza area cheat sheet
area = π (d/2)² or π d² / 4
10 in pizza 78.5 sq in
12 in pizza 113.1 sq in
14 in pizza 153.9 sq in
16 in pizza 201.1 sq in
18 in pizza 254.5 sq in

Memorize 78, 113, 154, 201, and 255 for the standard US pizza sizes and you can do most comparisons in your head. Divide the price by the right number and pick the lower result.

Pizza size versus pizza area

The single most important fact about pizza math is that doubling the diameter quadruples the area. A 16-inch pizza is four times as much pizza as an 8-inch, not twice. That comes from the π r² formula? when r doubles, r² multiplies by 4.

This is why the marginal cost of going up a size is usually a bargain. From 12 to 14 inches, the diameter gains 17%, but the area gains 36%. Pizzerias rarely raise the price by 36% when they bump up a size. They raise it by 25% or 30%, leaving the larger pizza as the better per-square-inch deal.

Did you know

The mathematician Eugenia Cheng built a 2012 viral demo showing that an 18-inch pizza has more area than two 12-inch pizzas combined. The math: 18-inch = 254 sq in; two 12-inch = 226 sq in. The single 18-inch wins by 12% even though it sounds smaller. The clip has been linked in news media and lecture slides ever since.

Standard sizes and areas

US pizzerias have settled on a fairly consistent menu of diameters, originating in the chain pizza explosion of the 1960s and 1970s. The numbers have not changed much since.

Medium 12 in
113.1 sq in
family of 3–4
Large 16 in
201.1 sq in
family of 5–6, party staple

European pizzerias mostly skip the size question? pizzas are individual portions, usually 28–33 cm (11–13 inches), and sold one per person. The square-inch comparison still works, just with centimeters and square centimeters as units. Multiply the diameter in cm by 0.394 to get inches if you want to compare across menus.

Two small or one large?

The classic question for any couple. Two 12-inch pizzas total 226 sq in. One 18-inch is 254 sq in. The single 18-inch is bigger by 12%, but it usually costs less than two 12-inch pizzas. Per-square-inch math nearly always favors the larger single pizza.

The exception is when you want two different toppings. A single 18-inch can be half-and-half, but you lose the option to order a vegetarian alongside a meat-heavy. Two 12-inch pizzas give you flavor flexibility at the cost of a small price premium. The square-inch math sets the floor for what that flexibility actually costs.

Party planning by group size

Plan on about 30 square inches of pizza per adult and 20 square inches per child. That is two to three slices for adults and one to two for kids, in standard 8-cut slices. For a group of 12 adults, you want at least 360 sq in? about two 16-inch pizzas or three 14-inch.

Use the per-square-inch math to choose the right combination. Three 14-inch (462 sq in) usually beats four 12-inch (452 sq in) by a meaningful margin once you compare prices. Two 18-inch (509 sq in) is often the cheapest path to feed a group of 12–15, and the unit math will show it.

Pizza deal tricks to watch for

Chain pizzerias use a few standard pricing tricks. The "two for $20" deal looks good but is often a wash compared to a single larger pizza. "Buy one, get one free" usually applies only to specific sizes and toppings. "Specialty pizzas" carry a markup that hides in the headline price even when the size matches a basic pizza.

Delivery fees can flip the math

A $3 delivery fee on a $12 pizza is a 25% premium that fully erases most per-square-inch savings. If you order delivery often, factor the fee and tip into the price before comparing. Three different pizzas on three separate orders can cost more in fees than the pizzas themselves are worth.

The other trick is the price of toppings. A plain cheese 14-inch at $14 is $0.091 per square inch. The same pizza loaded with five toppings at $22 is $0.143 per square inch? a 57% premium for ingredients that cost the shop maybe $3. If you compare a loaded pizza against a plain one, the plain one always looks like the better deal on paper.

FAQ

Compute the area of each pizza (π × radius²) and divide its price by that area. The pizza with the lower price per square inch is the better value, regardless of which is cheaper on the menu.
No, it is four times the size. Diameter doubles, but area scales with the square of diameter. (14/7)² = 4. This is the most common pizza-math mistake.
Almost. Two 12-inch pizzas total 226 sq in. One 18-inch is 254 sq in — about 12% more pizza in a single pie. If the 18-inch is priced near the cost of two 12-inch, it is usually the better deal.
In the United States, chain pizzas usually run $0.07–$0.10 per square inch, and local pizzerias $0.10–$0.15. Specialty wood-fired and gourmet pizzas can exceed $0.20 per square inch. The calculator normalizes these so you can compare any two.
Not directly — it assumes round pizzas. For a rectangular Sicilian or Detroit-style pizza, compute area as length × width and divide by the price. Then compare to the per-square-inch price of any round pizza.
Area = (π / 4) × diameter². The constant π/4 is about 0.7854. So a 12-inch pizza is 0.7854 × 144 = 113 sq in. Memorize 113, 154, and 201 sq in for 12″, 14″, and 16″ pizzas — the three most common sizes.
Strictly, yes — toppings add cost. The calculator measures crust area only, which is the right base when both pizzas have similar toppings. If one is plain cheese and the other is a loaded supreme, the loaded pizza is worth a higher price per square inch.
The calculator only compares the pizzas themselves. Real total cost adds taxes (typically 6–10% in US states), delivery fee ($3–$6), and tip (15–20% of subtotal). Add these to each pizza's price before comparing if you want a full-cost comparison.
Plan on about 30 sq in of pizza per adult and 20 sq in per child — roughly two to three slices each. A 16-inch pizza (201 sq in) feeds 6–8 adults. For 12 people, plan on two 18-inch or three 14-inch pizzas.
Usually, but not always. Pizzerias sometimes use a small pizza as a loss leader or charge premium prices for the very biggest. Always compute price per square inch — the calculator does it instantly — rather than assume bigger is cheaper.