What is a credit card size?

The size of a standard credit card is 3.37 x 2.125 x 0.0625 inches as per ID-1 standard of the International Standard ISO/IEC 7810. These sizes are also the same for debit cards, ATM cards, national IDs, driver licenses, etc.

Following are the credit card sizes & dimensions in different measuring units.

Credit Card Size	Width	Height	Thickness	Corner Radius
Inch	3.37 Inch	2.125 Inch	0.0625 Inch	0.125 Inch
Centimeter (cm)	8.56 cm	5.39 cm	0.159 cm	0.318 cm
Millimeter (mm)	85.6 mm	53.98 mm	1.588 mm	3.18 mm
Pixels (72 DPI)	242.64 px	225 px	4.5 px	9 px
Pixels (300 DPI)	1011 px	637.5 px	18.75 px	37.5 px

So, in summary, a credit or ATM card size is 3.37 inches (85.6 mm) in width, 2.125 inches (53.98 mm) in height, 0.0625 inches (1.588 mm) in thickness, and have a corner radius of 0.125 inches (3.18 mm) as per the defined ID-1 size in international standard ISO/IEC 7810. This size is also known as CR80.

Credit Card Thickness

The ISO/IEC 7810 specifies that all Credit Cards or other IDs, including (ID-1, ID-2, ID-3 & ID-000) should have a thickness of 0.76 millimeters (0.0312 inches).

The actual thickness of a credit card slightly varies from card to card if you include the extruded text on credit cards.

The thickness of a credit card also depends on the construction material used to construct a card. For instance, an apple credit card is made of titanium and is around 0.0325 inches thick, slightly thicker than 0.0312 inches. On the other hand, I have seen plastic cards as thick as 0.036 inches.
The thickness of credit cards is often measured in Mils. One Mil is the 1000th part of an inch. So 0.0312 inches translated to an exact 31.2 Mils.

How did the credit card size get standardized?

The generic size of a credit card is based on the first credit card issued by Bank of America in 1958. Of course, that size was not the same as we see today, but it was close. So we can say that Bank of America is the one who decided the size of a credit card for the first time.

Similarly, cards issued for ATMs in the 60s & 70s also played a vital role in credit card size standardizations.
For example, the first ATM bank card was issued by Barclays in London in 1967 had the same size we have at the moment. In the united stated, Chemical Bank issued its first ATM card in Long Island.

And, the first POS machines also got introduced after a few years in 1973 by IBM. The cards used for the POS machines were the same issued for ATMs helping to increase the demand for a bank card.

Over time, ATM & POS machines saw tremendous growth in adoption by banks and merchants across the globe. However, since there were a few ATM & POS machine manufacturers, luckily, the card sizes remained the same across the industry.

Since the credit card size was quite convenient in handling, companies & governments started to assign the same size to business cards, hotel cards, licenses, and other ID cards. This standardization made it easier for people to organize these cards in their wallet pockets. Imagine the chaos if you had 6 different size cards to organize in your wallet that has all the same size pockets?

When the types & companies dealing with credit cards boomed, in 2003, the International Organization for Standardization and the International Electrotechnical Commission (IEC) issued a standard ISO/IEC 7810:2003, which provides guidelines for different types of cards & their sizes.

Below is the summary of the size guidelines listed in the ISO standard.

Name	Size in mm	Size in inches	Details
ID-1	85.6 x 53.98	3.4 x 2.1	Most banking cards and ID cards
ID-2	85.6 x 53.98	4.1 x 2.9	French and other ID cards. Visas.
ID-3	85.6 x 53.98	4.9 x 3.5	United States government ID cards
ID-000	85.6 x 53.98	1 x 0.6	Mobile SIM cards

The latest version of the standard is ISO/IEC 7810:2019, issued in 2019-12.

Are all credit cards the same size?

Luckily, even before the standardization started, all credit cards and debit cards were the same sizes. This was mainly due to a few suppliers making the ATM & POS machines for all banks across the globe.

Later on, the size became a norm and helped using the same card everywhere.

The ISO standard makes sure that all cards have the same size, especially the ID cards, which were being made in different sizes before the standard was issued.

Since the credit cards were defining the size of pockets in wallets, most wallet manufacturers also standardized the pockets for other items like transparent pocket for a wallet size photo.

What is a credit card made of?

Credit & Debit cards are normally made of plastic, and to provide an additional strength against twisting & bending, multiple plastic thin sheets are laminated together. This also helps avoiding cracks propagation.

The center layer is mainly made of PVC plastic resin known as Polyvinyl Chloride Acetate. Multiple materials, pigments, and shiny particles are introduced in the center layer to give it a premium look and finish.

Plastic also provides an additional advantage of hot stamping the digits on the card. Since hot-stamped data on the card remains there for a longer period of time; as a result, banks don't have to replace the cards too often.

The thickness of a credit card is around 0.03 inches, and a plastic card of this much thickness is quite stiff to absorb all the abuse it will face.

The back of the credit card has a magnetic strip that is directly printed on the card. The magnetic strip stores related encrypted data required to make a transaction.

Additional Read:
1. HOW TO PROTECT A CREDIT CARD FROM GETTING DAMAGED IN A WALLET?
2. ARE MAGNETIC MONEY CLIPS SAFE FOR YOUR CREDIT CARDS?

Font size of credit card numbers

The font size on a credit card is around 12-16 points. However, different banks use different sizes as there is no underlying standard for the font used on a credit card.
Similarly, there is no standard for the font type or name, but mainly a monospace font like Courier, Consolas, Lucida Console / Lucida Sans Typewriter, etcetera are used. It's again at the discretion of the issuing bank to use whatever font they like.

Credit Card's Lamination Pouches Size

The laminating pouches used for protecting a credit card are exactly ‎3.38 x 2.13 x 0.01 inches in size, which is slightly larger than a standard credit card.

You can also find credit card sleeves from Amazon, which come in different sizes & most of them are RFID protected. The average size I calculated was 3.5 inches in length and 2.25 inches in height. A sleeve of this much size will easily fit a standard credit card.

Comparison of a credit card with other items

Below are a few images showing the comparative size of a credit card with different daily usage items.