Paper Products

What are the Different Paper Sizes?

Paper Sizes

Many of you may think paper sizes are pretty self explanatory and what more can we explain about them. Well, a lot actually. There is a number of paper size standards used throughout the world today. Europe, America, Columbia and Japan all use different standards when measuring paper. However, the two most used paper measurement standards come from the ISO & the ANSI.

International ISO Standard

The first paper standard system is the International ISO Standard 216. This system is mostly used throughout Europe.  There is a lot of math involved when figuring out how the sizes are determined but here is the basic understanding.

International ISO Standard 216 paper sizing guide

  • This paper sizing method is all based on a ratio of square root of 2. The purpose of this is that if you divide the paper into two equal halves than you will still have a ratio of. This means you can make folded brochures of any size by using a larger sized piece of paper. For example an A4 sheet of paper can be folded to make the smaller A5 brochures without losing the exact dimensions of an A5 sheet of paper.

American National Standards Institute (ANSI)

The second paper measurement standard is the one we use here in the US. The American National Standards Institute or ANSI. This is also in use in Canada & Mexico. Although the ANSI labels the sizes with letters (ANSI A), they are more commonly known as Letter, Legal and Ledger.

American National Standards Institute or ANSI paper sizing guide

  • This standard for measuring paper is centered on the “letter” size (8.5 × 11). This concept is similar to the ISO standard of folding a piece of paper in half would create two sheets of paper in the next size down. However, as a result of this formula it causes the paper to have two alternating ratios.

Comparing the Standards

Still feeling overwhelmed by all the math and sizes available? No worries, we created this handy chart below to help you understand the exact ANSI measurements & their ISO counterparts.

ANSI Paper Sizes

Inch * Inch


ISO size

ANSI A (Letter)

8.5 × 11

Standard size for typical piece of paper



8.5 × 14

Legal documents & real estate documents


ANSI B (Ledger/Tabloid)

11 × 17

Drawings, diagrams, large tables



17 × 22

Flip charts



22 × 34

Technical drawings, posters



34 × 44

Technical drawings, posters


Copyrights © 2024, Jam Paper & Envelope. All rights reserved.