Paper Size comparison tool
A
A4
210 x 297 mm
US
Letter
216 x 279 mm
What is the difference between A4 and Letter?
The primary difference between A4 and Letter is that A4 is taller and narrower (210 × 297 mm) compared to Letter (216 × 279 mm).
In terms of surface area, A4 is 3.5% larger than Letter.
An A4 piece of paper measures 210 × 297 mm or 8.3 × 11.7 inches. Cutting it in half will create two A5 sheets of paper. A4 is part of the A series.
A Letter piece of paper measures 216 × 279 mm or 8.5 × 11 inches. Letter is part of the US series.