Credit cards are in the shape of a Golden Rectangle. If you ever need an easily accessible example of a golden rectangle illustrating the proportions of the golden section, all you need do is to pull out a credit card or drivers license.

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Standard sized credit cards are 54mm by 86mm, creating a ratio of 0.628, less than a millimeter off from a perfect golden ratio or golden section of 0.618, the reciprocal of 1.618.

Sandeep says

I was looking for the standard size of Credit card. Are you sure the size you have mentioned is correct!!

Gary B Meisner says

Yes. See https://en.wikipedia.org/wiki/ISO/IEC_7810. The official US size is 53.98 x 85.60 mm, so the 54×86 stated is correct to within fractions of a millimeter. It’s not exactly a golden ratio, but close enough for making quick very close approximations.

Eamonn Cooney says

The Golden Mean or Ratio appears in mathematics and in nature. https://en.wikipedia.org/wiki/Golden_ratio

Gary B Meisner says

See also our articles on mathematics, life and beauty.

Michael Ossipoff says

The above-stated credit-card dimensions differ from the golden ratio by about 2%..

If the golden ratio were intended, then there wouldn’t be that 2% departure from the golden ratio.

But the close similarity suggests that maybe that shape is perceived as neither too long nor too short

Michael Ossipoff

Gary B Meisner says

As an update, after this article was first written, ISO standards were released in 2003 that state the dimensions of a credit card to be 85.60 mm x 53.98 mm. These numbers were apparently converted from the English sizes 3 3/8″ x 2 1/8″. The golden ratio of 85.60 is 52.90. So while that is a 2% difference, it’s only a difference of only 1 mm. This is not visibly perceptible, so the credit card still serves as a nice, handy reference for evaluating golden ratio measurements.