The diameter of a 7-inch pizza is 17.78 cm. The size of a pizza is inches, 1 inch (in)=2.54 cm, and seven inches refers to a diameter of seven inches, that is, 17.78cm. For people with a small appetite, a seven-inch pizza can be eaten by 1 to two people, while a large appetite can only be eaten by one person.

Inch is a unit of length used in the United Kingdom (UK, that is, the United Kingdom (Commonwealth) and its former colonies), abbreviated in English.

Conversion:

1、 1mil= 1/ 1000inch=0.00254cm=0.0254mm。

2、 1inch= 1000mil=2.54cm=25.4mm。

3. In the British system, 12 inch (inch) is 1 foot (foot), and 36 inch is 1 yard.

4. 1 inch =25.4mm (digital sensor).