Guide to Standard Book Sizes – Book Design 101

Three blue books in standard book sizes/

Welcome to Book Design 101 – a handy guide covering all the basics of what you need to know when publishing your first book. In this episode, we’ll look at how big – or small – your book can be, covering the standard book sizes in various areas of the world.  

If you’re interested in formats and covers – check out this article.

What are the standard book sizes?

Let’s start with the standard answer – it depends. :)

Mostly – it depends on your location. Book sizes will be different in Europe and in the US, but also in the continental Europe and the UK. There are also regional preferences – if you’re interested in checking out all the possibilities, I recommend checking out – a website that lists all the standardized paper sizes used across the world and allows you to compare them in different measuring systems.

And if you’d prefer an abridged version – here’s a list of the book sizes that I work with most frequently a book designer.

Standard book sizes in Europe

Image of three blue rectangles in trim sizes popular in Europe.

Europe uses a standardized paper system, in which sizes are divided into three groups – A, B, C, and then numbered from 0 to 10.

There are two common A sizes used in publishing and that’s A4 – 210 x 297mm (8.3 × 11.7”), and A5 – 148 x 210mm (5.8 × 8.3”), as well as one B format, B5 – 176 x 250mm (6.9 × 9.8”).

However, these formats are only the starting point – there are multiple variations that are sometimes even more popular.

If you’re publishing a novel, you might want to consider either A5, or a smaller size – 130 x 205 mm, 135 x 210 mm, or 140 x 215 mm.

If you’re publishing a non-fiction book, a good option would be B5, or slightly smaller – 170 x 240 mm, 170 x 230 mm, 160 x 220 mm, 160 x 240 mm.

And if you’re publishing a children’s book with a lot of illustrations, then you might want to start with A4 or a variation of it – like 210 × 280mm or 200 × 250mm.

The formats that I personally work with most often are 170 x 240mm, A5 (148 x 210mm) and 130 x 205mm.

Standard book sizes in the United States

In the US, the most common book sizes you’ll encounter are:

For novels – 4.25 x 6.87″, 5 x 8″, 5.25 x 8″, 5.5 x 8.5″, 6 x 9″.

For non-fiction: 5.5 x 8.5″, 6 x 9″, 7 x 10″.

The ones that I worked with most often were 6 x 9″ and 5.5 x 8.5″.

Standard book sizes in the UK

Despite technically being part of Europe, UK has its own set of standard sizes:

A-Format: 178 mm x 111 mm
B-Format: 198 mm x 129 mm
Demy: 216 mm x 135 mm
Royal: 234 mm x 156 mm

 If you’d like to see more variations, here’s a good resource: UK Book Publishing.

Print on Demand vs. printing independently

Keep in mind that when you’re using a Print on Demand service – such as Kindle Direct Publishing (KDP) or, for example, Books on Demand (BoD) in Norway – your choices regarding book size are going to be limited to what your chosen platform offers. Self-publishing sites often offer also different sizes for softcover and hardcover formats, which is another thing that’s worth keeping in mind.

In contrast, if you’re printing via a regular printing company, it’s usually possible to choose whatever size you’d like – however, if you choose something truly uncommon, be prepared for a higher printing cost.

What size should I choose?

There are several factors that you might want to consider when answering this question:

  • Genre – if you’re publishing a novel, it might be better to go with a smaller size rather than a big one (unless you have a lot of detailed illustrations).
  • Length – if your book is very long, choosing a slightly bigger size will let you limit the amount of pages.
  • Cost – given a similar page count, it’s generally cheaper to print smaller books than bigger ones – especially when using a POD service. You might want to try out different variations using royalties calculators that are usually available on POD websites.


Here’s one for:

That’s it!

I hope you found this short article useful – let me know if you think it’s lacking something, or if you have an additional question.

I’m always up for a chat – get in touch via  

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