Pizza Size Calculator
Compare two pizza options by diameter and price to determine which gives you more pizza per dollar. The area of a pizza increases with the square of the diameter, so a larger pizza is often a much better deal.
Pizza pricing exploits geometry. A 16-inch pizza isn't 33% bigger than a 12-inch pizza — it's 78% bigger by area. Most pizzerias mark up the larger size only 40–60% higher in price, which means the bigger pizza is almost always a better deal on a per-square-inch basis. The same trick works in reverse: those "small" personal pizzas at $9 are often the worst value on the menu when you compare area-to-price.
This calculator does the math: enter the diameters and prices of two pizzas, and it returns the area, price per square inch, and which is the better deal. The area formula uses the Pythagorean-derived classic — π × radius² — and the diameter-to-area scaling is quadratic, which is what makes a 14-inch jump from 12 to 16 inches feel like "a little bigger" but actually means almost twice the pizza.
This is the same math behind every menu optimization article, every "two mediums vs one large" debate, and every restaurant pricing strategy. Once you can do the area-and-price calculation in your head, you'll never order the smallest pizza on the menu again.
Inputs
Results
Best Deal
Pizza B is the better deal
Pizza A Area
113.1 sq in
Pizza B Area
201.1 sq in
B equals
1.8 of Pizza A
Price Per Square Inch
Formula
How to use this calculator
- Enter the diameter and price of two competing pizza options (e.g., the medium and the large at your local place).
- Read the price per square inch for each.
- The lower per-sq-inch number is the better dollar deal — usually but not always the bigger pizza.
- For "buy one get one half-price" promos, calculate the effective per-pizza price first, then run the comparison.
- For two-small-vs-one-large, run both as separate entries and double the small's sq inches.
- Remember the calculator only compares area — not toppings, crust style, or hunger sizing.
Worked examples
Domino's pricing comparison
**Scenario:** Domino's offers a 12" medium pepperoni for $13.99 and a 14" large for $15.99. **Calculation:** 12" area = π × 6² = 113.1 sq in. Unit price = 13.99/113.1 = $0.124/sq in. 14" area = π × 7² = 153.9 sq in. Unit price = 15.99/153.9 = $0.104/sq in. **Result:** The large pizza is 19% cheaper per square inch ($0.104 vs $0.124). For an extra $2, you get 36% more pizza. Always order up if you can finish it (or like leftovers — pizza reheats well).
Two mediums vs one large
**Scenario:** Local pizzeria: two 12" mediums at $11 each, OR one 16" large at $17. Which is more pizza? **Calculation:** Two 12s: 2 × 113.1 = 226.2 sq in total area for $22. Unit price = $0.097/sq in. One 16: 201.1 sq in for $17. Unit price = $0.085/sq in. **Result:** The 16" large beats two 12s on per-sq-inch by 14% AND costs $5 less for slightly less area. Choose two 12s only if you want different toppings on each pizza, or to feed people in two locations.
Personal pizza trap
**Scenario:** Pizzeria sells 6" personal pizzas for $7 and 14" large pizzas for $16. The personal one looks cheap. **Calculation:** 6" area = π × 3² = 28.3 sq in. Unit price = 7/28.3 = $0.247/sq in. 14" area = 153.9 sq in. Unit price = 16/153.9 = $0.104/sq in. **Result:** Personal pizza costs 2.4× more per square inch. Ordering one personal is paying ~140% premium for portion control. If you want a smaller meal, order a 14" large and freeze leftovers — still cheaper per slice than the personal.
When to use this calculator
**Use pizza area math when:**
- **Ordering takeout or delivery**: most menus offer 3–4 sizes; the per-sq-inch math almost always favors the largest you can finish. - **Feeding a crowd**: a 16" pizza yields ~6–8 dinner slices vs ~10–12 party-sized slices. Plan area per person rather than slice count. - **Comparing two pizzerias**: chain X may charge $14 for 14", chain Y charges $13 for 12". Per square inch, X is the better deal. - **Evaluating promo offers**: BOGO half-off promos sometimes still come out worse per sq-inch than simply ordering the largest single pizza. - **Restaurant menu design**: knowing area economics helps with pricing tiers; small mark-ups on large sizes drive larger ticket sizes.
**Servings to plan for:**
- **Light eaters**: 2 slices of a 12" pizza (about 35–40 sq in). - **Average appetite**: 3 slices of a 14" pizza (about 60 sq in) or 4 slices of a 12". - **Big eater**: 4–5 slices of any size, or a personal 10" pizza solo. - **Party**: plan ~50 sq in (about ⅓ of a 14") per adult, ~25 sq in per child.
**Crust style affects "real" pizza:**
- **Thin crust (NY, Roman)**: the area math is honest — flat, even, ~80% topping coverage. - **Hand-tossed**: edges curl up, ~90% useful area. - **Deep-dish (Chicago)**: depth matters more than area — but you also need fewer slices to feel full. - **Stuffed crust**: outer ring contains cheese instead of being plain dough; "useful" area increases.
**The 14-inch rule:** 14 inches is the median chain "large" size in the US (Domino's, Pizza Hut, Papa John's). It's usually the best dollar-per-square-inch unless they're running a promo on a different size.
Common mistakes to avoid
- Comparing diameters as if they were linear with price. A 14" pizza isn't "17% bigger than 12"" — it's 36% bigger by area.
- Ordering personal pizzas to "eat less." Per square inch they cost 2–3× the large; eating half of a large costs less and provides the same amount.
- Ignoring slice count vs slice size. A 12" cut into 12 slices and a 16" cut into 12 slices give very different slice areas. Sometimes you want bigger slices, sometimes more of them.
- Comparing across crust styles. A 14" thin crust and a 14" deep-dish have very different total food content; per-sq-inch alone underrates deep-dish.
- Forgetting delivery fees in unit price math. A $3 delivery fee makes a smaller pizza disproportionately worse per sq-inch.
- Not accounting for promo coupons. "$5 large with code" can make a "wrong size" the right choice for a single meal.
- Treating Sicilian-style square pizzas as round. Use length × width instead of π × r².