A3 vs. A4 Size Paper Differences and Why It Matters.

If you’re not in the office technology business, terms like A3 or A4 might not mean much to you. But when choosing a multifunction printer, A3 or A4 is one of the most important distinctions you need to know.

What is A3 Size vs. A4 Paper?
A3 and A4 refer to international standard paper sizes as defined by the ISO 216 standard.

• An A3 size print measures 297 mm x 420 mm (11.69 x 16.53 inches) — this roughly equates to ledger or tabloid size paper (11 x 17) in the United States

• A4 paper size measures 210 mm x 297 mm (8.27 x 11.69 inches), slightly larger than U.S standard letter size paper at 8.5 x 11 inches

Source: https://www.gflesch.com/blog/differences-between-a3-and-a4