Compare area of two round pizzas.
Pizza area grows with the square of the diameter, so a 16" pizza is nearly double the area of a 12", not one-third larger.
Compare cost per square inch to find the best deal.
This is a real-world example of why linear intuition fails for area comparisons — people routinely underestimate how much more pizza a modest diameter increase actually delivers, which is exactly why upsizing at a pizzeria is usually the better value.
12" pizza area ≈ 113 in²; 16" pizza area ≈ 201 in² — the 16" is 1.78× larger.
Because area scales as diameter², a small size bump is a big area bump. A 20% larger diameter = 44% more pizza.
Rough rule: 3 slices per adult. A 16" pizza (8 slices) feeds about 2–3.
Yes — the same diameter-squared relationship applies to any circular item, from cakes to skillets, so the same 'bigger is a better deal than it looks' logic holds generally.