ISO/IEC 7810

The standard defines both metric and imperial measurements, noting that:[4] Numeric values in the SI and/or Imperial measurement system [...] may have been rounded off and therefore are consistent with, but not exactly equal to, each other.

The original design was made using the Imperial measurement system.The ID-1 format specifies a size of 85.60 by 53.98 millimetres (3+3⁄8 in × 2+1⁄8 in) and rounded corners with a radius of 2.88–3.48 mm (about 1⁄8 in).

It was previously used for the Romanian, Icelandic, German, French and many other identity cards.

ID-2 was previously also used for driving licences (including Finnish, Swedish and Icelandic) before those changed to the ID-1 format.

[6] ID-000 specifies a size of 25 by 15 millimetres (1 in × 9⁄16 in), with one corner slightly (3 mm or 1⁄8 in) bevelled.