What is what size is printer paper?

Here's information about standard printer paper sizes:

The most common printer paper size is <a href="https://www.wikiwhat.page/kavramlar/Letter%20Size">Letter Size</a>, primarily used in North America. It measures 8.5 x 11 inches (215.9 x 279.4 mm).

Outside of North America, the most common size is <a href="https://www.wikiwhat.page/kavramlar/A4%20Size">A4 Size</a>, which measures 210 x 297 millimeters (8.27 x 11.69 inches).