A4 Paper Size

Coming from the United States, I thought letter size paper (8.5 x 11 inches) was the most common paper size.  I was surprised to find out that the A4 size (8.3 x 11.7 inches) common in Japan is also the most common in the world!  The 8.5x11 inch letter size is only the standard in the US and Canada.

In the 1920's, Dr. Porstmann of Germany published a document proposing a standard for paper which would later change the world. Dr. Porstmann's theory quickly became DIN approved, which is a standard in Germany meaning 'Deutsches Institut für Normung'. In English, DIN translates as 'German Institute for Standardization'.

A4 became a standard in the late 1970's. However, even though the standards were introduced in the early 20th century, it took more than 50 years for the standard to be recognized worldwide.