Pizza Size Calculator
Compare pizza value by area and price per square inch.
A bigger pizza usually beats two small ones — compare by area, not diameter.
How the Math Works
The Pizza Size Calculator uses the fundamental formula for the area of a circle: area equals pi multiplied by the radius squared. Since we typically know a pizza's diameter rather than its radius, the formula becomes area = π × (diameter/2)². This calculation gives us the total surface area of the pizza in square inches, which creates the mathematical foundation for comparing different pizza sizes on an equal footing.
Practical Applications
To use this calculator practically, simply enter the diameter and price of any pizza you're considering. The calculator determines the total area and then computes the cost per square inch. Compare this value across different sizes and prices to identify which option gives you the most pizza for your money. For example, a 12-inch pizza priced at $15 might have a lower cost per square inch than an 8-inch pizza at $8, making it the better value despite the higher total price.
Day-to-Day Use
This calculation helps you make smarter purchasing decisions when ordering pizza or comparing food portions in general. Instead of being misled by marketing that emphasizes 'family size' labels or focusing solely on total price, you can quickly determine which pizza delivers the most food for your budget. This saves money on frequent pizza nights and prevents the disappointment of realizing you could have gotten significantly more pizza for the same amount you spent. The calculator also applies to other circular foods like flatbreads, calzones, or even comparing container sizes at the grocery store.
Worked example
14 in → 154 in². An 18 in is 254 in² — 65% more pizza.
FAQ
Why compare per in²?
Because area, not diameter, is what you actually eat.