The humble eBook is a fascinating topic. At the most basic level, an eBook is just a book published in a digital format. In modern terms, however, an eBook is usually a specific kind of book, usually written for marketing purposes, either to build an individual's thought leadership, a brand's expertise, or as a general resource for an industry. As well, many eBooks take the form of extended case studies, white papers, and reports.
Due to their flexibility, it's not uncommon to want to know how to produce such a work. And, since you're likely on this site to learn exactly that, let's discuss it.
In the broadest sense, an eBook can be extremely long. Indeed, some of the longest novels ever written are available as eBooks, which is, if anything, a more convenient way to consume them rather than in dozens of volumes of printed work.
The shortest eBook, meanwhile, would likely be a children's book, with only a few hundred words. Of course, in these cases, graphic design and imagery take up the bulk of the book, and if a picture is worth a thousand words…
If I'm going to give you one general answer, it would be "as long as it needs to be."
If it doesn't get long enough, it will fall short of its purpose, leaving people wondering why they bothered to read it. On the other hand, if it goes on too long, it may bore readers or drive them away with a combination of density and lack of usability.
Of course, this isn't a valuable answer, so let's look at various factors to consider when planning an eBook.
The first thing you need to do is determine what the purpose of your eBook will be.
Fiction eBooks, for example, can be as long as they want to be but often aim for lengths similar to published works. So, a "short" fiction eBook might be a compilation of poetry and clock in at a few thousand words. Or, it might be a novella and be around 25,000 words. Or it might be closer to an average fiction novel, at 70-80,000 words.
Marketing eBooks will virtually never reach that length. Some of the longest, best eBooks in marketing are still no longer than 10,000 words. High-end "thought leadership" eBooks may be something like 12 chapters, with 25 pages per chapter. At 200 words per page (which is reasonable or even a little cramped depending on the page layout), you're looking at 40,000 to 60,000 for the extreme end of vanity projects.
Meanwhile, a shorter lead-generation eBook is going to be significantly shorter than just about anything else. Most marketing and lead magnet eBooks tend to be closer to 1,000 on the short end (usually accompanied by many illustrations, charts, and data) or as much as 5,000 for a more blog-like eBook.
In fact, in many cases, a lead magnet eBook is simply a blog post that has been expanded. If you write a "10 tips to create top-tier content" blog post, you could then write a "25 pro tips to create top-tier content" eBook to offer as a lead magnet.
Since the audience browsing this site is largely made of freelance writers and the businesses that hire them, you're likely most interested in marketing eBooks and books to sell, so those are the two most common forms you'll be looking into. Thought leadership and brand building eBooks tend to be longer, while lead magnet eBooks tend to be shorter.
The price that you ask for your eBook is generally going to be another determining factor, but it's not as simple as longer = better.
When you're offering an eBook for free, it's usually for brand building and awareness purposes. In this case, the word count is likely to be around the 5,000-word mark because you want to have enough space to showcase your authority and expertise.
When you "charge" something like an email address or opt-in as the price of admission, the ideal length actually drops. This is where the 1,000-word up to 5,000-word range is ideal. You don't want your eBook to be so long that the lead never reads it because then, even though you have their email address as a lead, your lead magnet didn't do anything to warm them up for you. A shorter book is easier to extract value out of.
These kinds of lead magnets tend to be offered in larger numbers, as well. A longer eBook might be produced annually or once every few years. Lead magnet eBooks might be quarterly or even monthly, depending on how hyper-targeted you want to make them.
It's a tall order, and it can be difficult to get right. To an extent, though, length isn't the only determining factor; you also need your content to be high quality. After all, you can write 100,000 words, but if they're all virtually meaningless, no one who buys it is going to care.
Price and value are often linked, but they are not the same thing. The value of an eBook comes from what the reader gets out of it.
Length isn't the only factor here. A dense, image-heavy, chart-filled eBook might actually only be around 2,000 words, but when every page is 50 words and a bunch of valuable graphs, that's a very beefy book. Similarly, a book of poetry has much more "value per word" than prose or marketing copy and may be accompanied by illustrations as well.
Another example might be a book of instructions. An eBook that serves as a usage guide or repair manual for a product may not have an exceptionally long word count, but much of the value is tied up in illustrations or screenshots instead.
Likewise, a book of templates (such as marketing email templates, for example) might be relatively short in words, but the value is more in the structures and patterns of those words than in the words themselves.
If the value of an eBook is tied up in non-word content, the actual word count can be shorter. If the value comes from prose, thought leadership, or analysis, the word count can be longer.
Another consideration, at least for some eBooks, is where you'll be publishing them. One of the most noteworthy examples is Amazon, specifically with Kindle Direct Publishing. Amazon used to allow eBooks of virtually any size or format, but at some point, they started rejecting and removing books under a certain length. It's somewhat unclear whether they define length by pure word count, page count, or a combination of both, but many books under around 1,000 words were purged to remove a lot of low-effort content.
Of course, if you're publishing your eBook on your own site, you are free to write it as short or as long as you want. There, the only limit on the length is how much you can convince people to read.
It's not about the number of words; it's about how you use them.
After all, not all words are created equal. You can convey the same point in ten words or in a thousand. Is one or the other better? Not necessarily.
Maybe your audience is more introductory or beginner-level. In that case, you might need a longer eBook to fully introduce and cover your topics. On the other hand, an expert purchasing an eBook might be offended or disappointed by an in-depth explanation of something they already know and, often rightly, assumed most of the people in that audience also knew.
So, to an extent, the ideal word count is a combination of too many factors to even say there's a single ideal word count. Instead, you need to consider the factors as modifiers and write to your needs.
You can also consider factors such as the other kinds of content you add into the eBook.
With modern eBooks, there's even the option to include links to other kinds of content, even as audio or visual media. A link to a YouTube video that is otherwise unlisted and unable to be viewed can be an added source of value that doesn't add to your overall word count.
Any length of an eBook can be good. You just need to sell it as such.
Since this site is dedicated to hiring freelance writers, another factor to consider is pricing. In fact, eBooks are one of the most expensive forms of content on a per-word basis, simply because their purpose and density are usually so much greater than the average website copy, social media posting, or blog writing.
As such, eBooks are expensive. They also tend to be priced on a per-chapter basis (at least for longer projects where chapters are applicable), with some number of chapters paid in advance. Since an eBook is such a big investment for both the client and the writer, an advance and a per-chapter completion payment are fairly standard.
The eBook creation process will also often involve multiple people with different skill sets, including a layout designer, a graphic artist for any illustrations, and of course, the core content writer. An editor may also be involved, and if it's being written based on verbal meetings or recorded speeches, even a transcriptionist. All of these roles require payment for their services.
As such, a good eBook can be a pricy endeavor. Even a short lead generation eBook can be anywhere from $500 to $2,000, and the longer "chapter book" eBooks designed for thought leadership and sale can be $5,000 or more.
Of course, the value you get out of a good eBook can be orders of magnitude higher, depending on how you calculate it. A good lead generation eBook can result in huge numbers of sales down the line and thought leadership can be difficult to quantify.
At the end of the day, all you really need to remember is that an eBook needs to serve a purpose, be aimed at a specific audience, cover a specific topic, and do so in as much or as little depth as is necessary. The more effectively you can do so, the better off you'll be, no matter how long the book ends up being. Hopefully, this information makes your eBook writing task a little simpler.