ISO 7810

Standards for financial and identity cards are set out by ISO.

All credit cards and debit cards, and most ID cards, are the same shape and size ID-1 as specified by the ISO 7810 standard:

• ID-1 = 85.60 × 53.98 mm (= 3.370 × 2.125 in)
• ID-2 = 105 × 74 mm (= A7)
• ID-3 = 125 × 88 mm (= B7)

Smartcards follow specifications set out in ISO 7816, and contactless smart cards follow the ISO 14443 specification (see also RFID).

The ratio of the ID-1 dimensions is approximately the golden section (or golden ratio) in order be as aesthetically pleasing as possible.

See also: Magnetic stripe card