Pizza Size Comparison Calculator
Compare two pizzas by price per square inch.
Results update as you type.
How it works
Bigger pizzas are often a far better deal than they look, and this calculator proves it by comparing price per square inch. You enter the diameter and price of two pizzas, and it returns the price per square inch for each and tells you which is the better value. The key insight is that a pizza's area, the amount of food you actually get, grows with the square of its diameter, not linearly. This means a 16-inch pizza has not a third more area than a 12-inch, but about 78 percent more, because doubling the width would quadruple the area. As a result, larger pizzas almost always cost less per square inch, so the bigger size is usually the smarter buy even when its sticker price seems high. The calculator computes each pizza's area using pi times the radius squared, divides the price by the area to get the cost per square inch, and identifies the cheaper one per unit of pizza. This same area-based comparison applies to any round food sold by size, and the underlying lesson, that area scales with the square of a dimension, is a handy piece of everyday math. Use it whenever you are choosing between sizes to get the most pizza for your money. Enter the two diameters and prices to see which is the better value.
Area = π(d/2)² ; value = price / area
A pizza's area grows with the square of its diameter, so a larger pizza has much more food than its width suggests. Computing each pizza's area with pi times the radius squared, then dividing price by area, gives the price per square inch. The lower price per square inch is the better value.
Source:Geometry / value comparison
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter pizza 1 — diameter, pizza 1 — price, pizza 2 — diameter and pizza 2 — price.
- 2
Adjust the options
Fine-tune any options to match your situation.
- 3
Read your result
Better value updates instantly as you type — no button to press.
Frequently asked questions
Why is a bigger pizza usually a better value?
Because a pizza's area grows with the square of its diameter, a larger pizza has disproportionately more food. A 16-inch pizza has about 78 percent more area than a 12-inch, not just a third more. So even though it costs more, the price per square inch is usually lower, making the bigger size the better deal.
How do you compare pizza value?
Calculate each pizza's area as pi times the radius squared, then divide the price by the area to get the price per square inch. The pizza with the lower price per square inch gives you more pizza per dollar and is the better value. The calculator does this for two pizzas and names the winner.
Why not just compare by diameter?
Diameter is misleading because area does not increase in proportion to it. Two pizzas might differ by only four inches in width but by a large amount in actual area and food. Comparing price per square inch accounts for the real amount of pizza, giving a fair comparison that diameter alone cannot provide.
Does this work for square or rectangular pizzas?
This calculator assumes round pizzas and uses the circle area formula. For a square or rectangular pizza, you would instead multiply length by width to get the area, then divide by price. The principle is the same: compare price per unit of area. For round pizzas, the calculator handles the geometry for you.
Should I always buy the bigger pizza?
By price per square inch the bigger pizza is usually cheaper, but value only matters if you will eat or use the extra. If a larger pizza leads to waste, the smaller one may suit you better despite a higher unit price. Use the calculator for value, then weigh it against how much pizza you actually need.