10cm * 7.6cm is the size of a 4-inch photo, and photo sizes are measured in inches. 1 inch is equal to 2.54cm. Generally, when we talk about X-inch photos, we are referring to the length of one side of the photo in inches. For example, a 5-inch photo would have a length of 2.54 * 5 = 12.7cm, and a 12-inch photo would have a length of 2.54 * 12 = 30.5cm.
ID cards and medical examination forms often use a smaller 1-inch size, which is 22 × 32mm. The second generation ID card has a size of 26mm × 32mm, while a standard 1-inch photo measures 25mm × 35mm. Passport and travel document photo standards have a size of 48mm × 33mm, with the width of the head ranging from 21mm to 24mm, and the length of the head ranging from 28mm to 33mm.
