10cm×7.6cm is the size of a 4-inch photo. The term “inch” in photo size refers to the length of one side of the photo in inches. When converted to centimeters, it is equivalent to a width of 2.5 centimeters. 4-inch photos are not commonly used and have irregular dimensions, so they need to be printed on 5-inch photo paper.

Photo sizes are usually measured in inches, with 1 inch being approximately equal to 2.54 centimeters. An X-inch photo means that one side of the photo is X inches (the shorter side for a 1-inch photo). For example, the length of a 5-inch photo is 2.54 × 5 = 12.7 centimeters, and for a 12-inch photo, it is 2.54 × 12 = 30.5 centimeters. Small one-inch photos measuring 22mm × 32mm are commonly used for identity cards, medical examination forms, etc. The photo size for the second-generation ID card in China is 26mm × 32mm, and the standard one-inch photo measures 25mm × 35mm. The size of Chinese passports/travel documents photos is 48mm × 33mm, with the width of the head ranging from 15mm to 22mm, and the length of the head ranging from 28mm to 33mm.