Paper and envelope sizes

Most of the world uses the A series; the United States and Canada use Letter. These pages give the exact sizes in both units and explain how to move between them.

In this section

Which page do you need?

  • For A4, A3, A5 and the other international sheets, open the A series chart.
  • For notebooks and books labelled B5 or B6, open the B series chart and check whether the product follows the international or the Japanese series.
  • For envelopes, open the C series chart. It also says which envelope holds which sheet.
  • For Letter, Legal, Tabloid and drawing sheets, open the US chart.
  • For printing a file on the other kind of paper, open A4 compared with Letter.

How these charts are made

International sizes are calculated from the rules of the standard and then compared with published tables. North American sizes are defined in inches and converted at exactly 25.4 mm per inch. Each page lists its sources and the date of the last check.