The inch of pizza refers to inches, named after its diameter. 1 inch =2.54 cm, and 9 inches is 9*2.54=22.86 cm. However, pizza is not strict to the millimeter, and with the invalid pizza edge, the real effective area generally needs to be removed from the area after the decimal point. For example, the diameter of a 9-inch pizza is 22.86 cm, and the actual effective area is generally 22 cm. 9-inch pizza is suitable for 1-2 people, 12 inch pizza is suitable for 2-3 people, and 14 inch and above pizza is suitable for 3-4 people and above.

Comparison of common pizza sizes: 6-inch pizza is15.24cm, 7-inch pizza is17.78cm, 8-inch pizza is 20.32cm, 9-inch pizza is 22.86cm, 10-inch pizza is 25.4cm,1.

Origin and application of inch

The word "inch" comes from the old English word "ynce", which comes from the Latin word "uncia" (meaning "one twelfth"). /kloc-in the 4th century, King Edward II of England promulgated the "standard legal inch". It is stipulated that the length of the head-to-head arrangement of the three largest wheat grains from the middle of the barley ear is 1 inch.

In building materials, the nominal diameter of pipes is in inches, not in city inches. In liquid crystal displays, the specifications are generally 17 inch, 19 inch, 23 inch, 27 inch and so on. In mobile phones, the screen sizes are generally 4.0 inches, 4.2 inches, 4.5 inches, 4.7 inches, 4.8 inches, 5.0 inches, 5.2 inches, 5.5 inches, 5.7 inches and 6.44 inches. In a tablet computer, the screen size is generally 7.9 inches, 9.7 inches, 12.9 inches. The size of the display screen is measured by the diagonal length, in inches.