What’s the Difference Between A3 and A4 Paper Sizes?

When choosing a copier or printer, understanding paper sizes is key to making the right decision. Around the world, many machines are labeled using the A-series standard—A3 and A4 being the most common. Even though these labels come from international standards, they’re widely used across the U.S. printing industry to describe paper capacity. 

A4 vs. A3: The Key Difference 

The primary difference between A3 and A4 is the maximum paper size the machine can handle: 

• A4 machines can typically print up to 8.5” × 14”, commonly known as Legal size in the U.S. 

• A3 machines can print up to 11” × 17”, which is referred to as Ledger or Tabloid size. 

What This Means for Your Office 

• An A4 copier or printer is designed for standard office tasks like printing documents, letters, and forms. It’s compact and ideal for day-to-day printing. 

• An A3 copier or printer is a larger machine capable of handling bigger jobs—perfect for printing spreadsheets, booklets, posters, or drawings that require more space. 

Quick Size Reference: 

Machine Type	Max Paper Size	Common U.S. Term
A4	8.5” × 14”	Legal
A3	11” × 17”	Ledger / Tabloid

Why It Matters 

Choosing between an A3 and A4 machine depends on your office’s printing needs. If you primarily print standard documents, an A4 machine is usually all you need. If your business requires large-format printing or more flexibility, an A3 machine offers the capability to do more.