Paper Size comparison tool
A
A3
297 x 420 mm
US
Letter
216 x 279 mm
What is the difference between A3 and Letter?
The primary difference between A3 and Letter is that A3 is taller and wider (297 × 420 mm) compared to Letter (216 × 279 mm).
In terms of surface area, A3 is 107.0% larger than Letter.
An A3 piece of paper measures 297 × 420 mm or 11.7 × 16.5 inches. Cutting it in half will create two A4 sheets of paper. A3 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.