In this video Julie Broad (founder of Book Launchers) explains why authors should decide a book’s size early, rather than discovering it at the end, and walks through the practical math and design considerations that determine page count, spine thickness, and print cost across major self‑publishing platforms. She starts by converting word count to page count using trim‑size‑specific words‑per‑page ranges (250‑350 wpp), then applies paper‑type multipliers (cream 0.0025, white 0.002252) to estimate spine width. The video highlights platform minimums for spine text (KDP 79 pages, IngramSpark 48 pages) and why designers often leave spines blank under 100 pages. Julie details the cost model shift at 110 pages on KDP (flat $2.30 vs per‑page pricing) and similar thresholds for premium color books, showing how page count directly impacts margins. She discusses design trade‑offs for short books—adjusting trim size, adding white space, or accepting a blank spine—to maintain perceived authority. Real‑world examples (Steven Pressfield’s 114‑page Do the Work, Mia Godfrey’s 212‑page Buried, Not Broken, Efrén Delgado’s 584‑page The Opposite Is True) illustrate how book length signals purpose (quick idea vs reference). Julie advises authors to set a target page count, calculate a corresponding word budget (e.g., 140 pages ≈ 38‑40k words for 5×8), and align the book’s size with the promise made to readers. She concludes with a call to action to book a consultation for writing, publishing, and promotion.
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Andrew Huberman's book landed on my doorstep a few weeks ago with a thud. 540 pages. And it got me thinking about a question that a lot of authors don't ask before they start writing, but they often ask later in the process. And that is, how big is my book gonna be? How big does it need to be? How book your big will be, because how big your book will be is not something that happens to you. It should be a decision or a series of decisions you make throughout the process of writing and developing a book. And it has implications for you, your sales, and of course, your reader. So if you're working on a book wondering if you're gonna have a mammoth, well, this video is for you. Hi, I'm Julie the Book Broad, founder of Book Launchers and your host here at BookLaunchers.tv. Book Launchers' mission is to help 100,000 books be discovered by 2030. I made a video about book size years ago. And it is still one of the most watched things on this channel. But the comments that have come in in more recent years, well, they have sharper questions like, how does 18,000 words look on a bookshelf? How do I figure out how big my spine is going to be? And why is my print cost different on KDP than Ingram? Well, this is the 2026 version with some math. So buckle up. Now, first, if you're thinking, how thick will my book be? Well, lots of people think they want a quick read, but how quick? And does it carry authority if it's too thin? Well, I don't necessarily think thick means more authority. It certainly doesn't mean readers are going to be excited about it. But let's figure out what this looks like, actually. So take your word count and divide it by 250 to 350 words per page, depending on your trim size, and you'll get your page count. Then you're gonna multiply your page count by 0.0025 for cream paper. I'll put the math numbers down below, but that's the calculation. There's a different calculation for white paper, but it's the same calculation at KDP and IngramSpark because they use the same paper stock. Now, why does this math matter? Well, first, your words per page. An interior page spread, which is usually gonna be a 5 by 8 or a 6 by 9, Well, with 5x8 trim with a readable font, that will give you somewhere around 250 to 280 words per page. With a 6x9, that's 300 to 350 words per page. So the exact same manuscript is a different book depending on decisions you make in your design and layout phase. Take a 20,000-word manuscript. That's a number a lot of you were asking about in the comments of that video. At 6x9, that's about 60 pages. That's small. And at 5 by 8, it's closer to 75. When you add your title page, your copyright, table of contents, and about the author, you might get to 85 or 90. Same words, different book. And this starts to matter. 2, 79 pages on KDP. That's their guideline. You can't put text on your spine until your book hits 79 pages. Anything under that and the spine has to be blank. So your cover has to do all the work. IngramSpark's line is lower. They'll allow spine text from 48 pages. But honestly, most professional designers still leave a spine blank under 100 pages because binding tolerance moves a few hundredths of an inch and your title ends up crawling onto the front cover. So it's a bit of a mess. So what does this mean? Well, you've written a tight, useful 18,000-word book. You're proud of it. It shows up and it has no name on the spine, which means on a shelf spine out, it's completely invisible. On a conference table, it's minuscule. In someone's office, it blends in with the paper. Your book is anonymous. So I'm not telling you not to write a short book. Short books can sell. I mean, Steven Pressfield has written several short books. This one, Do the Work, it's 114 pages and It's selling well and has for a long, long time. It's got a powerful idea. That's an important part with a short book. But I'm telling you that if you're going to write a short book, you need to know that you're making a trade. Now, his title does fit on the spine, but you're going to want to adjust the trim size, which they did, and get creative with how the inside of your book looks. There's a lot of white space inside of his book to spread this out. So the upside is this is a really fast, powerful read for your reader. The downside is you need to go into design making decisions around making it still look like a powerful book. So go to a smaller trim size to push your page count up, give each chapter a proper page opening, lots of white space, or you end up accepting that blank spine, which I don't recommend. Now, decide it, don't discover it at the end. And make do because you weren't prepared. Number 3, 110 pages. That's really where money starts to show up. In KDP in the US, a black and white cost in paperback in a standard trim costs you a flat $2.30 to print all the way up to 110 pages. 24 pages, 60 pages, 109 pages, same price, $2.30. At 110 pages, the model flips. Now it's $1 fixed plus a little over a penny per page. So a 300-page book costs you about $4.60, and if you went large trim, say 7 by 10, that flat rate is $2.84, and the per-page rate jumps about a penny and a half. So the same 300-page book is now costing you $6.10. Now, the math changes a lot when you start doing premium color, so brace yourself. The flip happens at 40 pages, and above it you're paying $6.50. and a half cents a page. A 200-page book costs $14 to print before you've made a cent. Now, check your own numbers in KDP Calculator before you commit. I've got the calculators below because this does change. But what I want you to think about is under 110 pages, your print cost is fixed, which means a short book has the best margin you will ever get on paper. If your book is a lead magnet for a $5,000 service, Short is not a compromise. It can be a good model. But again, I wouldn't go so short that my title doesn't fit on the spine. Now, number 4, your paper multiplier. The spine question that kept coming up, well, each paper type changes the spine. So white paper is times 0.002252, cream paper 0.0025, premium color pages has a different calculation. Cream is slightly thicker than white. So the identical manuscript on cream actually gives you a fatter spine. And sometimes that's exactly what you want. IngramSpark uses the same stock, so the same multipliers apply, with one little thing that's different. Lightning Source rounds your page count up to an even number before it calculates. So if your book is 213, they're figuring the spine on 214. Is that going to ruin your cover? No. But if your designer has put your title in a font that fills the spine to the edge, a hundredth of an inch is the difference between clean and crooked. Very important. Now, hardcover doesn't follow any of these formulas at all. So every platform uses its own stepped table for case laminate. Don't calculate it. Pull the template from the printer every time for every book. Now let's talk about that mammoth versus the ant. So let me show you 3 different books. All right, as I mentioned, Do the Work, 114 pages. You can read this sitting in the doctor's office waiting for your appointment, I bet. But when you read it, you feel like you can build something. There is a powerful message inside. Buried, Not Broken by Mia Godfrey, 212 pages, 5 by 8, a spine just under half an inch. That's a book somebody finishes in a few hours and then hands to their sister. Then there is Efrén Delgado's The Opposite Is True, one of our clients. Oh, Mia Godfrey's one of our clients too. 584 pages, 6 by 9. Actually, this is the hardcover, so it's not the 6 by 9. But for him, 584 pages is not a mistake. He built this book on purpose. Somebody picks this up and thinks, wow, that person did the work. His size is a signal, and the signal is accurate. His stories are brilliant. It's well-researched. It's thoughtful. Truth is, I love this book, and I have never finished it. Andrew Huberman, I love his podcast, and the book is so big, I honestly don't think I'll ever sit down and read it. I'll probably flip to different sections and reference it, but I'm not going to read it because it's too daunting. And I have to think he knew that going in. I think it reads exactly like his podcast. It's thorough and just not the thing I'm going to curl up with on a Sunday. I like to think he intentionally designed the book to be a reference guide versus a page-turning read. Don't know. Efrén Nohes' book was really big and too big to read cover to cover in a weekend. But every time I pick it up, I'm glad I did. The stories are great and he wrote it for the reader that will feel that way every time they pick it up. Before you write another chapter, pick your target. Say it out loud. I'm going for 140, 180-page book, and work backwards. And you have a word budget, right? If you're going for 140 pages at a 5 by 5 by 8.5, that's 38,000 words, 40,000 words. Now you've got a sense of how big you're going for. And if you want help with writing, publishing, and promoting your books, you don't have to think about any of these things. Let's chat. You can book a call at booklaunchers.com/apply. Now ultimately, I tell our clients that a book should be as big as it needs to be to fulfill the hook of the book to the reader. And at the same time, nobody really wants a 100,000+ word book to read these days. So if you find yourself with 150,000 words, I think you've really just found yourself with a 3-book series. Your book size is a promise you make to the reader before they read a word. A thick book like Protocols or Opposite Is True, well, that is promising reference. And authority and detail and probably not something you're going to read from COVID to cover. A mid-sized book promises a transformation of some kind and a small book promises a powerful idea packing a punch and yeah, that's a generalization and there's always exceptions to these rules but I promise you that if you create a giant book, your content better be exceptional because readers have to spend a lot of time to get through it and if your book is short with a powerful idea, Your reader will be a lot more forgiving. Break any of these promises and your reviews will haunt you for life. So decide, are you creating a mammoth or an ant and why? And why will it matter to your reader? Because nobody ever finishes a nonfiction book that doesn't deliver on its promise, whatever that promise is to its reader. And nobody also thought, I wish that book had been longer. I'll see you on the next video.
