Common Paper Sizes: A Guide

Writing with a fountain pen is an enjoyable experience all on its own. But what makes for a significantly smoother writing session is using fountain pen friendly paper! It's true, paper can make all the difference.

When you first look into fountain pen friendly paper and notebooks, it can be a bit overwhelming to understand all of the sizes and options available. Goulet Pens always lists the product dimensions and technical specs on our product pages, so you can be informed about the products you're interested in. However, it can still be confusing to understand different product sizes that you are unfamiliar with when shopping online.

We're here to help you understand paper and notebook sizes relative to each other, so you can compare new products to some of your trusted favorites to understand the size.

What Do All These Letters and Numbers Mean?

Long story short, there are several series of "standards" that define paper sizes. The most commonly used is the International Standard (ISO) A, B, or C series. There's also the American National Standards Institute (ANSI) series, but more on that later.

Most of the notebooks we sell are sourced from outside the US, so they primarily come in one of the International Standard (ISO) A series, sometimes the ISO B series. 

OK. So what does that mean? 

The letter (ie "A") determines which series it falls under, and the number (ie "4") refers to a specific sequential size within that series.

It might be helpful to use some illustrations.

ISO A Series

The "A" series starts with the largest A0, which is a square meter in surface area.

Each size uses an aspect ratio of¬†1:‚ąö2 which actually dates back to the late 1700's. This is a unique property, because when a rectangle of this aspect ratio is folded in half, it retains the same ratio. The ISO A series was later formalized in 1921 and is still widely used.

So basically, each ISO paper size is exactly half of the next larger size in the same letter series.


ISO series size sheet

And yes, there are massive A0, A1, A2, and A3 sizes.... but not in anything we sell as they're not very shippable! Basically take the A4, double it to get an A3. Double that to get an A2, double that to get the A1, and double that to get the A0. It's huge.

Here you can see how the sizing scales ‚ÄĒ an A4 is two A5's stacked on top (sideways), A5 is 2 A6's stacked on top (sideways) and so on. Keep scrolling to see examples of how¬†the more common paper sizes compare to each other.

Here are two of the most popular sizes ‚Äď the A4 and the A5.


A4 vs A5 comparison

One A4 cut in half "hamburger style" will get you an A5.

A5 vs A6 images

The same with an A5 ‚ÄĒ slice it in half and that's the size of an A6.


A6 and A7 images

A savvy reader has likely guessed it ‚ÄĒ Two A7's is one A6.

Fun Fact: sixteen A7's would make an A4. #math

ISO "B" Series

The B series comes from the ISO "B" family ‚ÄĒ the slightly wider and skinner cousin of the A series. The lettering and numbering works similarly to the "A" series -- as the numbers increase, the size decreases. B5 is bigger than B6, and so on.

The "B" series is slightly larger than the "A" series, so if you were to put them in sequential order, it would be something like: A4, B5, A5, B6, A6, etc.

Here's the A4 compared to the B5.

A4 vs B5 size

And here's the A5 compared to the B5.

A5 vs B5 Notebook Size Comparison labeled with dimensions

Overall, the B5 is an excellent in-between size and is a very popular choice for journaling, especially Bullet Journaling. 


ANSI "A" Series

In America, we're most familiar with the ANSI (American National Standards Institute) for paper sizes, particularly the "A" size. That's our standard 8.5" by 11" loose leaf notebook paper that we all used in school, and that we use in our printers.

The ANSI series works similar to the ISO series but kind of in reverse -- as the letter goes up (i.e. A, B, C), the size doubles. So an ANSI B (11" x 17") is twice the size of an ANSI A (8.5" x 11"). 

The ANSI A is not too different from the ISO A4 size.


A4 vs ansi size

As you can see, it's a very close match! We don't have a ton of fountain pen friendly paper available in the American 8.5" x 11" letter size, so the A4 would be a good alternate choice for you.


Choosing a Size

A4 notebooks and notepads are very popular for note taking as they have ample room for long meeting or class notes, and often come with more sheets than smaller options. A4 is a great choice for students and professionals alike! 

Shop our A4 collection here.

A4 notebooks


The next size down we have is the B5. It's smaller than the A4 but bigger than the A5 so it's a perfect "goldilocks" for some folks. With a bit more height than an A5 it will prove to be more comfortable if you find those a bit on the small side and it's a bit more portable than a full A4 size. 

Shop our B5 collection here.

B5 notebooks


You've learned above that A5 is half the size of A4 and that makes it the perfect size for a lot of different things! Whether it's a planner, journal, cookbook, scrapbook, or just a pad for notes at home, the A5 size is among the most popular with our customers. 

Shop our A5 collection here. 

A5 notebooks


A6 is once again half the size of your A5 ‚ÄĒ seeing a trend? The A6 is what we usually call "small" but it's not¬†too¬†small. Just big enough for a grocery list, notes for the family, or to keep in your work bag just incase.¬†

Shop our A6 collection here.  

A6 notebooks


Everyone loves miniature things, but don't underestimate a pocket sized notebook. For notes on the go or a to-do list always within arms reach, you cannot beat a pocket sized notebook or pad. These are in the 3.5" x 5.5" size range, not quite in any of the above standard series.

Shop our Pocket-sized collection here.

Pocket sized notebooks


Since 2006 the Traveler's notebook cover, accessories, and corresponding books have been taking the world by storm. Think of a Traveler's Regular size as a blown up version of a checkbook. It's slim enough to stay in a pocket, but long enough to provide meaningful writing space. These unique notebooks have endless possibilities. 

Shop our Traveler's Regular sized collection here. 

Traveler's Regular sized notebooks


The little sibling to the "regular" sized Traveler's book is about the size of a Passport. The corresponding books are great company for your favorite explorer, prove useful for holding information while you travel, and come in various line options. If the Regular is too big, this Passport size might hit the spot. 

Shop our Traveler's Passport Size here.

Traveler's Passport Size


As you can imagine, there are lots of other choices out there. Our "Other Sizes" category contains smaller-than-pocket sized notebooks like A7 and B7, as well as notebooks that are a bit larger or smaller than the normal sizing conventions including the one ANSI "A" letter size notebook we offer.

You may be surprised to find one of your favorites in this category! 

Shop our collection of Other Sizes here.

other sized notebooks



As you can see, paper sizes are pretty easy to understand, once you have the helpful hint as to how paper sizing works! 

If you like numbers, here's a cheat sheet for the approximate dimensions for these common paper sizes:

ISO A Sizes

  • A0: 841 mm x 1,189 mm (33.11 in. x 46.81 in.)
  • A1: 594 mm x 841 mm (23.39 in. x 33.11 in.)
  • A2: 420 mm x 594 mm (16.54 in. x 23.39 in.)
  • A3: 297 mm x 420 mm (11.69 in. x 16.54 in.)
  • A4: 210 mm x 297 mm (8.27 in. x 11.69 in.)
  • A5: 148 mm x 210 mm (5.83 in. x 8.27 in.)
  • A6: 105 mm x 148 mm (4.13 in. x 5.83 in.)
  • A7: 74 mm x 105 mm (2.91 in. x 4.13 in.)

ISO B Sizes

  • B0: 1028 mm x 1456 mm (40.48 in. x 57.32 in.)
  • B1: 707 mm x 1000 mm (28.66 in. x 40.48 in.)
  • B2: 514 mm x 728 mm (20.24 in. x 28.66 in.)
  • B3: 364 mm x 514 mm (14.33 in. x 20.24 in.)
  • B4: 257 mm x 364 mm (10.12 in. x 14.33 in.)
  • B5: 182 mm x 257 mm (7.17 in. x 10.12 in.)
  • B6: 128 mm x 182 mm (5.04 in. x 7.17 in.)

North American ANSI Sizes:

  • ANSI A: 8.5 in. x 11 in. (215.9 mm x 279.4 mm)
  • ANSI B: 11 in. x 17 in. (279.4 mm x 431.8 mm)
  • ANSI C: 17 in. x 22 in. (432 mm x 559 mm)
  • ANSI D: 22 in. x 34 in. (559 mm x 864 mm)
  • ANSI E: 34 in. x 44 in. (1118 mm x 864 mm)

Most of these sizes are used in the broader print industry, but now you understand a little more about how these series work. There's even an ISO "C" series, and so much more. If you really wanna geek out, check out this Wikipedia article; there's a lot there.

If you have any questions or would like a recommendation, don't hesitate to Contact Us!

If you're interested in any of the notebooks featured in the infographics, you can find more information on each product page at Goulet Pens.

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