A5 is a designation for a specific size of paper that measures 148 millimeters by 210 millimeters, or approximately 5.8 inches by 8.3 inches. It is part of the ISO 216 standard, which defines various paper sizes used internationally. A5 is commonly used for notebooks, flyers, and personal planners due to its convenient size for handling and portability. In terms of usage, A5 paper is often favored for printing documents, invitations, and brochures. It is half the size of A4 paper, making it easy to create booklets or folded materials. The A5 format is popular in both personal and professional settings for its versatility.