A4 is the most common paper size worldwide and conforms to the international paper size standard (International Organization for Standardization (ISO 216), adopted by all the countries in the world with the exception of the U.S. and Canada. A4 paper measures 8.27" x 11.69" and is longer and narrower than U.S. 8.5" x 11" letter size paper. This small difference can cause big printing and distribution issues with documents sent to and received from other countries. With our wide selection of A4 paper, you can eliminate paper size compatibility challenges. Stock A4 paper in your printer, copier and fax machines to prevent document cut-off and distribution problems.