A Pizza for Eight Is 13.86 Inches, Not Sixteen
Servings follow area and area follows the square of the width, so feeding eight instead of six multiplies the diameter by the square root of four thirds: exactly 8 root 3, or 13.8564 inches, about 15.5 percent wider. Sixteen inches carries 16/9 of the area and would feed 10.67 people, so the reflex over-orders by nearly three servings. Allowing a one inch bare crust moves the answer down to 13.55, because a wider pizza spends proportionally less of itself on edge.