Old, yellowing, worn-down books opened

Why Books Have Always Been Shaped like Rectangles

Happy National Read-a-Book Day: the second day of the year reserved exclusively for book lovers, aside from National Booklovers’ Day on August 9! If you want to see the article I did for that literary holiday, click here to see the many short books you can read in one day (but of course not all at once)…

To celebrate this special day for book lovers everywhere, we’ll be taking a look at the book’s design origin: what exactly makes books that certain rectangular shape that we bibliophiles have come to know and love?



Well, there are three angles to approach how the “book” came to look this way: science, history, and math. Okay, it’s more complicated than that, but those would be in the simplest terms.

Now, before you sign off out of fear of actually being brought back to school at the mere mention of these subjects, just hear me out while I list out how each one has brought us a monumental step forward in achieving the ideal shape of our rectangular readables, print or electronic.

First, the scientific factor explains how, on an anatomical level, the object to be read is specifically designed the way it is intended to be read by its human reader: by being seen and held.


Little girl reading small book on green couchImage via Unsplash


First off, in order to keep readers’ attention while they go through a text at an appropriate speed, the reader’s amount of saccading, or the act of scanning or flicking our eyes back and forth while reading, should be made as manageable as possible, so a single line of text should be between 45 and 75 characters, the ideal count being at 66.

And secondly, the reader should be able to hold the object in their hands, so the books’ proportions have been adjusted accordingly to fit within a person’s hands, and that is why the typical book looks as though it were two hands coming apart or together.

Funnily enough, before this handheld change, the first bound books were usually much taller in size and put on pedestals to be read! Can you imagine anything like that today? (Unless you don’t want to get your book dirty or wet, or maybe you love your books so much, you literally put them on a pedestal. Now, that shows dedication!)



Next, the historical angle is based on the vast history in book publishing, an industry that processes and sells these texts to their public and is expected to pay attention to their readers’ preferences in reading the material that’s published and to act accordingly to meet those needs.


History books on dark bookshelves in libraryImage via Unsplash


Of course, before there were books, there were scrolls, and these scrolls, when folded and stitched together on a single edge, became the first codices, the precursor to the modern book.

So, since the early codices, or texts, were taken from scrolls, they took on original scrolls’ sizes, which were of course long, but over time, the sizes began shrinking and were starting to look like modern-day books… but not quite. For example, the original first-century codices were typically in four columns, but by the fourth century, the text per page has been reduced down to two, though we are more familiar with the one column going down a single page in our pleasure-reading books.

Of course, there were practical issues to consider: this might go without saying, but the typical book isn’t wider than taller in size due to the amount of stress that the width could inflict on the spine. Therefore, in order to stand upright, they always have to be on the slim side.

Even after all of this, the proportions weren’t all there, but the general handheld position our books assume was cemented into place.

Okay, history lesson over!



And finally, the mathematical angle explores how the numbers, including a very special number, play a key role in forming the right shape these texts should physically embody.


Math compass on graphs on desk

Image via Unsplash


Don’t worry: this section will be a little bit shorter than either of the former two sections, mostly because it is way too complicated to totally get into here!

So, in short, the mathematical reasoning behind why our books are “rectangularized” the way they are can all be boiled down to something as simple as… a secret magic number.

Books written and published during the Renaissance era have been proven to have the “golden canon of page construction,” the secret number having been revealed to be 2:3, though this number for perfectly constructing books may vary from publisher to publisher (which quite possibly explains why the lengths of books may slightly vary).

In fact, this “golden ratio” applies not just to book construction: it is also observable in nature and used in other aesthetic fields, such as art, architecture, and music! If there’s a magic number for book lovers to hold onto for when the time is right, it might be this one!

And there you have it: we wouldn’t have our lovable rectangles that can fit in the palms of your hands without science, history, and (incredulously) math. So, when you pick up your next read (today might be the day to start), tell your book (and the many others you may have) that you love them, rectangle and all, and to never be square…


Featured Image via Unsplash