Difference Wiki

A4 Paper Size vs. Letter Paper Size: What's the Difference?

Edited by Aimie Carlson || By Harlon Moss || Published on January 13, 2024
A4 Paper Size is an international standard size of 210mm x 297mm, commonly used globally. Letter Paper Size is a North American standard size of 8.5 inches x 11 inches, widely used in the U.S. and Canada.

Key Differences

A4 paper size, measuring 210mm x 297mm, is part of the ISO 216 standard, making it a common choice for documents worldwide. Letter paper size, at 8.5 inches x 11 inches, is a standard size in the United States and Canada, but it's not as widely used internationally.
A4 is the go-to paper size for most international correspondence, academic papers, and standardized forms. Letter size is predominant in the U.S. and Canada for everyday printing, office documents, and school papers.
The A4 size has a slightly narrower and longer dimension compared to the letter size, affecting the layout and formatting of documents when switching between the two. Letter size, being slightly wider and shorter, can alter the appearance of documents designed for A4.
For global businesses and institutions, A4 is the standard to ensure uniformity in document sizes across different countries. Letter size is often used in North America for local businesses, schools, and government documents.
In printing and photocopying, settings for A4 are common worldwide, while letter size settings are a default in North American printers and copiers.

Comparison Chart


210mm x 297mm (8.3" x 11.7")
8.5" x 11"


ISO 216 standard
North American standard

Common Usage

International documents
U.S. and Canadian documents


Slightly narrower and longer
Slightly wider and shorter

Printer Settings

Standard in global printers
Standard in North American printers

A4 Paper Size and Letter Paper Size Definitions

A4 Paper Size

A4 size is widely used for documents and printing outside North America.
Ensure all the flyers are printed on A4 paper size for the overseas branches.

Letter Paper Size

Letter size paper is not part of the ISO standard series.
Remember, letter paper size is not the same as the ISO A4 size.

A4 Paper Size

A4 paper fits international filing systems and office equipment.
Organize these documents in A4 size to fit our filing cabinets.

Letter Paper Size

Letter paper is slightly wider and shorter than A4.
Adjust the layout as the flyer is to be printed on letter paper size, not A4.

A4 Paper Size

A4 paper size is slightly longer and narrower than letter size.
Design the brochure keeping in mind that A4 paper size is different from letter size.

Letter Paper Size

Letter size is commonly used for personal and business documents in the U.S. and Canada.
The school assignments must be submitted on letter paper size.

A4 Paper Size

A4 is part of the ISO standard series for paper sizes.
We use A4 paper size as it's the ISO standard for our global communications.

Letter Paper Size

Letter paper size is a North American standard measuring 8.5 inches by 11 inches.
Print the document on letter paper size for the U.S. office.

A4 Paper Size

A4 paper size is an international standard measuring 210mm x 297mm.
The report should be printed on A4 paper size for the international conference.

Letter Paper Size

Letter size paper is a standard for everyday printing in North America.
Set the printer to letter size for these meeting handouts.


What are the dimensions of A4 paper size?

A4 measures 210mm x 297mm (8.3" x 11.7").

Are U.S. printers typically set up for letter paper size?

Yes, most U.S. and Canadian printers accommodate letter size.

Is A4 part of a standardized series?

Yes, A4 is part of the ISO 216 series.

What is letter paper size used for?

Letter size is used for documents in the U.S. and Canada.

Is A4 paper size used globally?

Yes, A4 is the standard in most countries outside North America.

Is letter paper size common outside North America?

Letter size is less common outside the U.S. and Canada.

Is A4 compatible with most copiers worldwide?

Yes, A4 is a standard size for copiers globally.

What is the aspect ratio of A4 paper?

The aspect ratio of A4 is 1:√2.

Can A4 be easily scaled to other sizes?

Yes, A4 scales proportionally to other ISO sizes like A3 and A5.

Do letter size papers fit in standard binders?

Yes, letter size fits standard North American binders.

Why is A4 popular in business and academia?

A4's international standardization and compatibility make it ideal for global use.

Are letter size papers typically wider than A4?

Yes, letter papers are slightly wider than A4.

Is A4 suitable for filing in the U.S.?

A4 can be used but may not fit standard U.S. filing systems.

Can letter paper size be used for international documents?

It can be, but A4 is typically preferred for international documents.

Do international offices need to adapt for letter paper size?

Yes, if they deal with North American documents.

Is A4 the same as European letter size?

No, European letter size is different and is typically A4.

Can A4 paper be used in North America?

Yes, but letter size is the standard in North America.

Why might someone choose A4 over letter size?

Due to its international standardization and wider global use.

What makes letter paper size unique?

Its dimensions of 8.5" x 11" are standard in North America.

Are there printers that don't support letter size?

Yes, especially in countries where letter size isn't standard.
About Author
Written by
Harlon Moss
Harlon is a seasoned quality moderator and accomplished content writer for Difference Wiki. An alumnus of the prestigious University of California, he earned his degree in Computer Science. Leveraging his academic background, Harlon brings a meticulous and informed perspective to his work, ensuring content accuracy and excellence.
Edited by
Aimie Carlson
Aimie Carlson, holding a master's degree in English literature, is a fervent English language enthusiast. She lends her writing talents to Difference Wiki, a prominent website that specializes in comparisons, offering readers insightful analyses that both captivate and inform.

Trending Comparisons

Popular Comparisons

New Comparisons