For the purpose of creating ID cards and badges, the most common plastic card size is the CR80 or ID-1 format. These designations refer to plastic cards measuring about the size of a credit card 85.60 mm by 53.98 mm (3.370 inches by 2.125 inches). The typical thickness for this type of card is 0.030 inches.

The majority of plastic ID cards created today utilize the CR80 format, however there are some exceptions. Thinner cards are sometimes used for printing business cards, while thicker cards are often required for IDs that incorporate RFID technology and must contain embedded antennas and circuitry. CR50 cards which measure 3.5 inches by 1.75 inches are sometimes used for access control for hotel rooms. And if you’ve ever owned a membership card for a gym or grocery store, you might be familiar with the tiny cards that hook to your keychain.