A Complete Guide to Printer Paper Dimensions for Everyday Use

Epic Tech Tips
Oct 31
4 min read

Printer paper comes in many sizes, and each serves a specific purpose. Knowing these dimensions helps produce neat, professional prints for home, school, or office use.

The A-series paper sizes, like A4 paper and A3 paper, are the global standard for printers. Each size is half the one before it, making them easy to scale.

A4 remains the most common for everyday documents, while A3 and smaller options fit creative needs.

Understanding paper sizes saves time, reduces waste, and ensures perfect printing every time.

Key Takeaways

A4 is the most common global printer paper size.
U.S. printers use Letter size (8.5 x 11 inches).
A-series paper sizes follow the ISO 216 standard.
Each A size halves the one before it.
Choose paper size based on document purpose and format.

Understanding Printer Paper Sizes

If you’ve ever stood in front of a printer wondering which paper size to use, you’re not alone. Paper sizes are more than just letters and numbers - they help ensure documents print correctly, look professional, and fit your needs. Understanding these dimensions can save time, reduce printing errors, and make your projects look their best.

The Standard Printer Paper Size: A4

When most people ask, “What size is printer paper?”, they’re usually referring to the A4 size. This is the most commonly used paper size worldwide, especially for home and office printing.

A4 Paper Dimensions: 210 x 297 mm (8.3 x 11.7 inches)
Usage: Letters, reports, forms, schoolwork, and standard documents.

In many parts of the world, including Europe and Asia, A4 is the default. In the United States, however, the standard printer paper size is slightly different-known as Letter size, measuring 8.5 x 11 inches.

The A Series Paper Sizes Explained

The A series of paper sizes is internationally recognized under the ISO 216 standard. Each size in the series is based on a consistent aspect ratio of 1:√2. This ratio ensures that when a sheet is cut or folded in half, the proportions remain the same.

Here’s a quick look at the most common A-series paper sizes:

Paper Size	Millimeters (mm)	Centimeters (cm)	Inches
A0	841 x 1189 mm	84.1 x 118.9 cm	33.1 x 46.8 in
A1	594 x 841 mm	59.4 x 84.1 cm	23.4 x 33.1 in
A2	420 x 594 mm	42 x 59.4 cm	16.5 x 23.4 in
A3	297 x 420 mm	29.7 x 42 cm	11.7 x 16.5 in
A4	210 x 297 mm	21 x 29.7 cm	8.3 x 11.7 in
A5	148.5 x 210 mm	14.85 x 21 cm	5.8 x 8.3 in
A6	105 x 148.5 mm	10.5 x 14.85 cm	4.1 x 5.8 in
A7	74 x 105 mm	7.4 x 10.5 cm	2.9 x 4.1 in
A8	52 x 74 mm	5.2 x 7.4 cm	2.0 x 2.9 in
A9	37 x 52 mm	3.7 x 5.2 cm	1.5 x 2.0 in
A10	26 x 37 mm	2.6 x 3.7 cm	1.0 x 1.5 in

Each smaller size is exactly half the area of the previous one. For example, two A4 sheets placed side by side equal one A3 sheet.

Common Uses for Different Paper Sizes

While A4 paper rules everyday printing, other sizes serve specific purposes:

A3 – Ideal for posters, charts, and large presentations.
A5 – Commonly used for booklets, invitations, and notepads.
A6 – Perfect for postcards or small flyers.
A0–A2 – Large-format printing such as blueprints, banners, or posters.

Knowing which size fits your purpose helps maintain consistency and professional presentation across documents.

How Paper Size Affects Printing

Choosing the correct paper size affects how text and images appear on the page.

A mismatch between printer settings and paper dimensions can lead to cropped edges, blank margins, or misaligned prints.

That’s why it’s important to set the correct paper size in your printer or design software before hitting print.

Tip: Most printers automatically detect A4, but always double-check your settings if using A3, A5, or custom sizes.

Why ISO Paper Sizes Are So Practical

The ISO system (used in Europe, Asia, and most of the world) has a big advantage: scalability.

Because every paper size keeps the same aspect ratio, an A4 document can be enlarged to A3 or reduced to A5 without losing proportion.

This makes resizing documents for printing or photocopying incredibly easy.

For instance, designers can create artwork in A4 and print it at A3 for a poster - no stretching or reformatting needed.

Paper Size vs. Paper Weight

While size determines the dimensions, paper weight affects how thick or durable it feels. Measured in grams per square meter (gsm), typical printer paper is 80 gsm, while brochures or covers use 120–300 gsm for a sturdier texture.

Combining the right size and weight ensures professional, high-quality prints for every purpose from business cards to banners.

US vs. International Paper Standards

It’s worth noting that not all countries follow the ISO system. The United States, Canada, and parts of Mexico use Letter (8.5 × 11 in), Legal (8.5 × 14 in), and Tabloid (11 × 17 in) instead.

When sharing files globally, this difference can cause layout shifts. That’s why professionals often export PDFs with embedded margins to ensure consistent printing anywhere.

Conclusion

So, what size is printer paper? The standard printer paper size is A4 (210 x 297 mm or 8.3 x 11.7 inches), though U.S. users often use Letter size (8.5 x 11 inches). Understanding both systems helps you choose the best format for your projects, whether you’re printing a simple document or a large poster. With this guide, you can now select the perfect paper size confidently every time.