A standard CD typically has a diameter of 120 millimeters (4.7 inches) and a thickness of 1.2 millimeters (0.05 inches). These dimensions are standardized by the International Organization for Standardization (ISO) and are commonly referred to as “12 cm” discs. There are also smaller CDs, such as mini CDs with a diameter of 80 millimeters (3.1 inches), but they are less common.
