C1 Paper Size Dimensions


648 × 917 mm


A C1 envelope measures 648 × 917 mm or 25.5 × 36.1 inches. An A1 piece of paper will fit into a C1 envelope. C1 is part of the C series, most commonly used for envelopes, and is defined by the ISO 269 paper size standard.

All C Envelope Series Paper Sizes →