International ISO

The International ISO business card size has dimensions of 74 mm x 52 mm, which converts to approximately 2.9 inches x 2 inches. With a surface area of 38.48 sq cm or 5.97 sq in, it is more compact than North American and European sizes. The ISO size fits inside a DL (110 x 220 mm) or C6 (114 x 162 mm) envelope.

This business card dimension corresponds to the ISO 216 A8 paper size standard defined in 1975. The ISO aimed to unify paper sizes worldwide by scaling based on halving areas. The resulting A8 size was identified as ideal for business cards - larger than ISO's A9 but still portable. The ISO 7810 standard for identification cards also defined a card size of 85.6 x 54 mm, just slightly larger than A8. The ISO 74 x 52 mm size is sometimes known as the A8, international standard, or credit card size. It allows easy printing, enclosure, and carrying of cards globally. Despite its benefits, the ISO size has seen most adoption in Eastern Europe and Asia rather than replacing North American and Western European formats.