Common Paper Sizes & How to Choose the Right One

Any writer can tell you, if you're journaling, sketching, or writing daily notes, choosing the right paper size can make all the difference in the world. But defining what the “right size” is? Well, that can be a little bit harder to answer. It all depends on your preference, writing style, and needs.

But finding the right paper size can make you feel a bit like Goldilocks. B6 might be too small. A4 might be too large. And A5? Well, that one is juuust right.

If all of this feels a bit like alphabet soup - keep reading. We have a comprehensive breakdown of the most common paper sizes, along with a few of our favorite picks to stock up on this year.

Pair your perfect paper size with one of our fountain pen journals for an experience that’s as smooth as your ink.

Understanding Paper Size Letters & Numbers

The letters and numbers used for paper sizes follow standardized systems that help categorize different dimensions of paper. The most common system, used internationally, is the ISO 216 standard, which includes the A, B, and C series. While this may seem a little foreign for Americans, that’s because it is! The United States and some parts of Latin America have not fully adopted the ISO 216 standard and, instead, use dimensions like “Letter” and “Legal” size – that is, unless you’re a stationery head or pen lover like us!

A-Series

The A-series is the most widely used for notebooks, journals, and office paper. It starts with A0, the largest size, and each subsequent size is half the previous one when folded in half parallel to its shorter side. Not to get too technical, but each scaling up uses the same aspect ratio, meaning you can scale up or down without distorting proportions. Here are a few of the most standard A-sizes and what they’re traditionally used for:

• • A0 (841 × 1189 mm / 33.1 × 46.8 in) – Large posters, technical drawings

  • A4 (210 × 297 mm / 8.3 × 11.7 in) – Standard printer paper, common notebooks

  • A5 (148 × 210 mm / 5.8 × 8.3 in) – Popular for journals and planners

  • A6 (105 × 148 mm / 4.1 × 5.8 in) – Pocket notebooks, small sketchpads

From top to bottom: A6, A5, A4. A0 not pictured.

B-Series

The B-series offers sizes in between the A-series for more flexibility. They’re slightly more squared and great for books, posters, and specialty notebooks. Two of the most common you’ll find are:

• • B5 (176 × 250 mm / 6.9 × 9.8 in) – Common for mid-sized notebooks

  • B6 (125 × 176 mm / 4.9 × 6.9 in) – Great for portable planners and journals

From top to bottom: B6, B5..

C-Series

C sizes are hardly spoken about and that’s because they tend to be reserved for envelopes for A-series paper. For example, a C4 envelope holds an A4 sheet without folding, and a C5 envelope fits an A5 sheet.

Photo by Joanna Kosinska via Unsplash.com

Most Common Sizes: Advantages & Disadvantages

A4: The Classic Workhorse

A4 paper (8.3” × 11.7”) is one of the most commonly used sizes worldwide, particularly in offices, schools, and professional settings. Comparable to US letter size that many of us are familiar with, A4 is large enough to provide ample writing space while still being manageable for filing and organizing. Writers and notetakers appreciate A4 for its versatility - it’s great for long-form writing, technical notes, and printing documents.

Disadvantages: While A4 provides plenty of space, it’s not the most portable option. It can feel too large for casual or on-the-go note and might be a bit cumbersome for everyday carry – and worse, run the risk of bending these pages more in a tightly-packed backpack!

Our A4 Picks:

• Endless Storyboard Spiral Notebook

• Yamamoto Fountain Pen Friendly Sampler A4 Tablet

A5: The Perfect Balance

A5 paper (5.8” × 8.3”) is a favorite among writers and journal keepers because it strikes a balance between portability and ample writing space. It’s roughly half the size of A4, making it more compact yet still large enough for comfortable writing. A5 notebooks are great for daily journaling, bullet journaling, meeting notes, and travel diaries. Because of its versatility, many high-quality notebooks, planners, and journals come in this size, making it a go-to choice for everyday use!

Disadvantages: While A5 is a well-balanced size, it might feel limiting for those who need extra space for diagrams, long notes, or sketching – or even if you just have a larger handwriting and are a longform writer!

Our A5 Picks:

• Rhodia Goalbook Notebook

• Leuchtturm1917 Hardcover Dot Gid Notebook

• Clairefontaine La Vie en Vosges Staplebound Notebook

From top to bottom: Rhodia Goalbook A5, Endless Storyboard Spiral A4..

B5: The Creative Canvas

B5 (6.9” × 9.8”) is slightly larger than A5 but more compact than A4, making it an excellent choice for those who want a balance of space and portability that each of the latter may lack in their respective ways. Like A5, it’s great for sketching and journaling, with just slightly more room to accommodate larger handwriting styles or artwork.

Disadvantages: Since B5 is not as commonly used as A4 or A5, it can sometimes be harder to find notebooks and refills in this size - that is, unless you’re shopping at Goldspot!

Our B5 Picks:

• Itoya Profolio Osasis Lined Notebook 

• Leuchtturm1917 Composition Hardcover Dot Grid Notebook

B6: The Versatile Performer

We love a B6 (7.1” × 10.1”) notebook because it offers a perfect compromise between the compactness of B5 and the expansive surface of A4. Its size makes it versatile for everything from notetaking to sketching. It's especially great for those who want a bit more space than A5, but without the bulk of larger formats like A4.

Disadvantages: Just like the B5 size, it can sometimes be hard to find refills for your favorite notebooks.

Our B6 Picks:

• Itoya Profolio Oasis Summit Notebook

• Dominant Industry The Ink Archiving Book

From top to bottom: Dominant Industry The Ink Archival Book B6, Leuchtturm 1917 Composition Hardcover B5..

Finding the right paper size is like discovering your perfect pen—personal, satisfying, and essential to your creative flow. But beyond just your preference, choosing the right size makes a difference in how you use your paper every day.

Let’s say you’re joining a pen pal exchange and have C4 envelopes, A4 paper allows you to write longer letters that fold neatly to fit. Prefer compact journaling? A6 slips easily into a coat pocket, while A5 fits snugly into most handbags and backpacks. For professionals, B5 offers more room than A5 for meeting notes without the bulk of A4. Artists, too, might opt for larger sketchbooks like A4 for drawings or B6 for casual doodling. Each size has a purpose that’s right for the user — whether it’s portability, compatibility with accessories, or maximizing writing space. And lucky for you, we have a wide array of options to get you started on your paper journey today!