Paper Size Guide: Standard Paper Dimensions Explained

Choosing the right paper size is an important first step when preparing artwork for print projects such as flyers, posters, brochures, and business stationery. From everyday office documents to large format posters, understanding standard paper sizes helps ensure your design fits perfectly and prints correctly.

This guide explains the international A-series paper sizes, how they relate to each other, and which sizes are commonly used in printing.

What Is the Most Common Paper Size?

The most common paper size worldwide is A4 (210 × 297 mm). It is widely used for office documents, flyers, brochures and everyday printing.

Most of the world uses the ISO 216 paper size system, also known as the A-series. These paper sizes follow a simple and logical structure where each size is exactly half the size of the previous one.

For example:

• A3 is twice the size of A4
• A4 is twice the size of A5
• A5 is twice the size of A6

This consistent scaling makes it easy to enlarge or reduce documents without changing proportions.

A-series paper sizes are widely used for:

• office printing

• marketing materials

• books and brochures

• posters and signage
  

Below is a quick reference chart showing the most common A-series paper sizes.

Paper Size	Dimension (mm)	Dimension (inches)	Typical Uses
A0	841 × 1189 mm	33.1 × 46.8 in	Large posters, architectural drawings
A1	594 × 841 mm	23.4 × 33.1 in	Posters, technical drawings
A2	420 × 594 mm	16.5 × 23.4 in	Posters, calendars
A3	297 × 420 mm	11.7 × 16.5 in	Posters, menus, presentations
A4	210 × 297 mm	8.27 × 11.7 in	Documents, flyers, brochures
A5	148 × 210 mm	5.8 × 8.3 in	Leaflets, booklets, invitations
A6	105 × 148 mm	4.1 × 5.8 in	Postcards, small flyers

Each size maintains the same aspect ratio of 1 : √2, which ensures designs scale correctly.

While the A-series includes many sizes, some are far more commonly used in everyday printing.

A4 Paper Size

A4 is the most widely used paper size in the world. It is the standard size for office documents, forms, letters, and many printed marketing materials.

A4 is commonly used for:

• flyers

• brochures

• reports

• presentation documents

Read more in our A4 paper size guide.

A5 Paper Size

A5 is half the size of A4 and is often used for compact printed materials.

Typical uses include:

• small leaflets

• booklets

• event programmes

• invitations

Read our A5 paper size guide for full dimensions and uses.

A3 Paper Size

A3 is double the size of A4 and is ideal for larger designs where visibility matters.

It is frequently used for:

• posters

• menus

• presentation materials

• marketing displays

Learn more in our A3 paper size guide.

A6 Paper Size

A6 is a smaller format commonly used for postcards and promotional handouts.

It works well for:

• postcards

• mini flyers

• promotional cards
  

Learn more in our A6 paper size guide.

DL is a popular paper size used for leaflets and envelopes.

DL dimensions are: 99 × 210 mm or 3.9 × 8.3 inches

DL is commonly used for:

• folded A4 leaflets

• promotional mailers

• menus

• envelope inserts

You can learn more in our DL size guide.

 

SRA paper sizes are slightly larger than the standard A-series sizes. They are used in professional printing to allow space for trimming and bleed.

For example: SRA3 measures 320 × 450 mm

This extra space allows designs to extend beyond the final trim area before being cut down to the finished size.

Learn more in our SRA3 paper size guide.

The best paper size depends on the purpose of your printed material.

Common examples include:

Flyers - A5 and A4 are the most popular choices.

Posters - A3 and A2 are commonly used for display printing.

Brochures - A4 folded formats such as tri-fold or half fold are widely used.

Postcards - A6 is a standard promotional size.

When designing artwork, it is important to set your document to the correct dimensions and include bleed if the design runs to the edge of the page.

Paper size is only one part of the printing process. The paper weight, usually measured in GSM (grams per square metre), also affects the look and feel of the final print.

For example:

80gsm - Standard office paper

170gsm - Typical flyer weight

250–350gsm - Used for postcards and lower quality business cards

400–800gsm - Used for high quality business cards

You can learn more in our GSM paper weight guide.

What Is the Most Common Paper Size?

A4 is the most commonly used paper size worldwide and is standard for office printing, documents, and many marketing materials.

Is A4 the Same as Letter Size?

No. A4 is slightly taller and narrower than US Letter size.

A4 - 210 × 297 mm

Letter - 216 × 279 mm

Why Are A-Series Paper Sizes Used?

The A-series system allows paper sizes to scale perfectly. Each size is half the previous size while maintaining the same proportions.

What Paper Size Should I Use for Flyers?

The most popular flyer sizes are A5 and A4 because they provide enough space for design while remaining easy to distribute.

If you want to learn more about specific paper sizes, explore our detailed guides:

A0 paper size

A1 paper size

A2 paper size

A3 paper size

A4 paper size

A5 paper size

A6 paper size

DL size guide

SRA3 paper guide

These guides explain dimensions, common uses, and printing tips for each format.

Quicklinks

Standard Paper Sizes Explained
Paper Size Chart
The Most Common Paper Sizes Used in Printing
What Is DL Paper Size?
What Is SRA Paper Size?
Choosing the Right Paper Size for Printing
Paper Size and Paper Weight
Frequently Asked Questions
Explore More Paper Size Guides