Take the 2-minute tour ×  As per the title. What are the
dimensions of a business card that fits in a wallet? (i believe
it is a global standard?)  Bonus marks if you can give the
history behind how it arrived at that dimension.  share|improve
this question  3 Answers 3  up vote 16 down vote accepted  It is
not as standard as one would hope. The common aspect ratios
range from 1.423 to 1.8.  For most ID cards and credit cards,
ID-1 from the ISO/IEC 7810 (Wikipedia) standard gives the
dimensions, which are 85.60 × 53.98 mm (3.370 × 2.125 in) with
an aspect ratio of 1.586. This is also the standard business
card size in many situations as it is highly pocketable.
Another size which could be considered somewhat international,
is the ISO 216-sized (Wikipedia) A8 = 74 x 52 mm (2.913 × 2.047
in) with an aspect ratio of 1.423. Though, personally, I haven't
seen many of these.  There are a few cultural variations. For
example here in Finland 90 x 50 mm (3.543 × 1.968 in) is common,
but ID-1 size is also quite common