How Many E-Books Can Fit on a Flash Drive?

I am quite the computer nerd, and have a lot of back-ups, old software, and family photos stored away on various hard drives. Over the past year of embarking on this archiving quest, I have become strangely fascinated with compression and storage efficiency, alongside cataloguing files.

Given the growing popularity of e-books, what with their handiness, friendliness to impaired readers, and environmental positives, I figured it would be interesting to figure out how many e-books (in an approximate manner) can be stored on an everyday flash drive.

E-Book Formats

There are many ways to store text, even full books, when it comes to the digital realm. Just to name some, there are: TXT, AZW, AZW3/FK8, KFX, PDF, and EPUB.

Although these all come with their own upsides and downsides, most people will want to stick with PDF or EPUB for a consistent reading experience across devices like their phone, tablet, Kindle, laptop, desktop, and so on.

EPUB and PDF typically come out to the same size. For text-only publications, EPUB generally wins by a small margin. However, I personally prefer PDF’s fixed nature, even if it sometimes takes up another megabyte or so of space.

Regardless, text-only PDFs and EPUBs are so tiny that this really doesn’t matter. For the sake of our hypothetical flash drive, using PDF may cost us a few books when compared to EPUB, but given this post’s goal of merely providing an approximate answer, we can dismiss this small discrepancy in file size.

If you are curious about PDF and EPUB as formats, consider researching their differences in your own time. As much as I would love to explain them myself, the differences in these fairly similar file formats are beyond the scope of this post.

Flash Drive Capacity

The main reason I am choosing to frame this discussion around a flash drive as our storage device is due to their general reliability, small size, expanding capacity, and increasingly accessible pricing as the years go by.

Since the turn of the millennium, flash drive sizes have grown from 8MB to as big as 4TB (500,000 times bigger than 8MB). Like most other storage mediums, flash drive capacity is usually incremented by 100%, so 8MB to 16MB to 32MB and so on.

To cover this question thoroughly, we will consider the range from 8MB to 4TB. With that explained, see below for the answer to how many books each flash drive (or any storage device of the same capacity) could hold!

Books per Capacity

For the sake of consistency, we will assume every book is text-only and requires 2.5MB of space to be housed. In reality, some works could be 1MB, whilst others are 5MB. We simply need a consistent number to approximate, so 2.5MB (based on my own PDF averages), seems like suitably round and reasonable figure. Outcomes will also be rounded to the nearest figure!

Below are the approximate books by capacity (treating 1GB as 1000MB):

And that answers that, in a very loose fashion. If you throw in compression—considering how much text-based files shrink—you could easily double the amount. However, these numbers assume a fixed size per book, alongside no use of compression formats like .zip and .7z.

Since most humans are unlikely to read more than 2,000 books in their lifetime, you could argue all anyone needs in an 8GB flash drive loaded with their preferred authors, topics, and genres.

Of course, if you want books with illustrations and pictures that aren’t compressed into a digital soup, then books will suddenly start ranging from 30–500MB depending on length and image quality. These variables are so hard to measure, and so varied between works, that it is not really worth considering.

However, one can definitely see the major benefits of e-books in this regard. To house 1.6 million books would take an immensely vast library and hundreds of people to micromanage, process, and upkeep it… not to mention the cost of acquiring books, paying wages, and replacing damaged or stolen titles, and the terrifying risk of them all being charred in a fire. Environmentally, there is also considering how many trees would have to be cut down, the impact of manufacturing the book, and the pollution from shipping them around.

It is incredible that we can carry so many stories and a world’s worth of information on a little digital stick that takes up the same physical space as a pack of chewing gum. At worst, these could also be stored on roughly A5-sized hard drive or even smaller SSD.

Although I will always prefer physical in most cases, digital surely has its perks, particularly saving on saving on space, improving portability, and (in the event of hosting a server or storing these in the cloud) global accessibility.