What are the specific sizes of 1-inch and 2-inch photos?

1-inch photo size: 2.7*3.6cm, 3*45 pixels.

the size of a 2-inch photo is: 3.5*4.9cm, 626*413 pixels.

the size of a photo is in inches, and 1 inch = 2.54cm. Usually, x inch refers to the length of the long side of the photo in inches. For example, 5 inches means that the photo length is 2.54x5=12.7cm；; 12 inches means that the photo is 2.54x12=3.5cm long.

Extended information:

A photo of a certificate is a photo used to prove identity on various certificates. The ID photo requires a bareheaded (hat-less) front photo. In the photo, you should normally see the contours of people's ears and the place equivalent to the Adam's apple. The background colors are mostly red, blue and white, and the size is mostly one inch or two inches.

Reference: Baidu Encyclopedia-Photo Size