The large pizza always wins
When the menu says "medium 12 inch" and "large 16 inch", your brain compares 12 and 16 and concludes: a third more. Wrong — and not by a little. What you eat isn't the diameter, it's the area. And area grows with the square of the radius.
1. How much more do you get?
A pizzeria sells a medium at 12 inches across and a large at 16 inches. What percentage more pizza is the large?
2. Compare two sizes
Drag the two diameters and see the circles at true proportion. The formula is the area of a circle: A = π × r². Because the radius is squared, increasing the diameter by 33% increases the area by 78%.
3. Two mediums or one large?
The classic table argument. The answer depends on the numbers — and now you can settle it instead of guessing. Enter the prices and see which one delivers more pizza per dollar.
Remember this: area changes with the square of the diameter. A pizza with twice the diameter holds four times the food. In practice the bigger pizza almost always delivers more food per dollar — and it also explains why two small pizzas rarely beat one large. The same reasoning applies to pans, TVs (measured by the diagonal!), cans, and anything sold by a linear measurement when what matters is area or volume.
Plan the party pizza
Work out how many pizzas to order for your headcount, and compare sizes and prices.
Open the Pizza Calculator →See also: Circle area · Barbecue · Lesson: the percentage trap