Paper Sizes Explained: A4 vs. US Letter

If you have ever tried to print a PDF from Europe on a US printer, you know the struggle. The bottom gets cut off, or the margins are wrong. Why?

The ISO Standard (A4)

Most of the world uses the A-series (A0, A1, A2, A3, A4). It is based on a clever mathematical ratio (the square root of 2). If you fold an A3 sheet in half, you get exactly A4. If you fold A4, you get A5. This makes resizing documents for print shops incredibly efficient.

The US Standard (Letter)

North America uses "US Letter" (8.5 x 11 inches). It is slightly wider and shorter than A4. This historical quirk dates back to the days of manual papermaking frames.

The Conflict

A4 is taller. If you print an A4 document on Letter paper at 100% scale, the footer usually gets cut off. Always remember to check "Fit to Page" in your printer settings!