When you reach the category section in your KDP setup, it can feel like a small step. You click a few boxes, save, and move on to pricing. But learning how to choose Amazon book categories is one of the most helpful things you can do for your book’s visibility, and it only takes a little research to do it well.

I’ve spent years helping authors research the keywords and categories for their books, and categories are one of the places where I see first-time authors leave the most opportunity on the table. Not because they did anything wrong, but because nobody explained how categories actually work. So in this post, I’m going to walk you through the exact steps I’d want you to follow, in plain language, so you can choose your three categories with confidence.

If you’d like the bigger picture first, my post on Amazon book SEO explains how your keywords, categories and book description all work together. This post zooms in on categories so you can get that one piece right.

What Amazon Book Categories Are (and Why They Matter)

The easiest way to think about categories is to picture a bookstore. When you walk in, books are arranged on shelves by subject, like Business, Self-Help, or Biographies & Memoirs, and each of those sections has smaller shelves inside it. Amazon works the same way. Amazon describes its book categories as digital shelves that help customers find books that match their interests.

Categories matter for two main reasons:

• They help readers who browse. Some readers don’t search at all. They click into a category they love and scroll. If your book is on the right shelf, those readers can find you.
• They decide which bestseller lists you appear on. Each category has its own bestseller list. A book in a very crowded category is competing with thousands of other titles, while a book in a well-chosen, more specific category has a much better chance of being noticed.

Categories also work hand in hand with your keywords. Together, they tell Amazon where to shelve your book and which readers to show it to.

How Many Categories Can You Choose on Amazon KDP?

Right now, KDP lets you choose three categories when you set up your book. Before mid-2023, authors could ask KDP support to add extra categories, but as Reedsy explains in its category guide, that’s no longer possible, and books are limited to the three you select.

One detail that surprises a lot of authors: categories are chosen for each format. Your ebook and your paperback each have their own category selections, and some categories are only available for certain formats. So if you’re publishing both, plan to choose categories for each one.

Because you only get three slots per format, each one is worth a bit of thought. That’s what the steps below will help you with.

How to Choose Amazon Book Categories in 6 Steps

Step 1: Get Clear on Who Your Book Is For

Before you look at a single category, take a minute to describe your book in one sentence: who it’s for and what it helps them do. For example, “a guide for new managers who want to lead their first team with confidence” points you toward very different shelves than “a memoir about caring for my mother through dementia.”

This sentence becomes your filter. When you’re looking at a category later, you can ask yourself, “Would the reader in my sentence browse this shelf?” If the answer is yes, it’s a good candidate.

Step 2: Look at Where Similar Books Are Shelved

Next, find three to five books that are similar to yours. Look for books written for the same reader, on a similar topic, and ideally published in the last few years.

On each book’s Amazon page, scroll down to the product details and look for Best Sellers Rank. Right next to it, you’ll see the categories that book is ranking in. Jot these down. After a few books, you’ll usually start to notice the same shelves showing up again and again, and that tells you where readers of your kind of book are already shopping.

Step 3: Browse the Category Tree Yourself

Now go exploring. Amazon’s Best Sellers in Books page lists the main categories down the side, and you can click into each one to see the smaller subcategories inside it. Keep clicking until you reach the most specific shelves that still describe your book honestly.

As you browse, keep in mind that the Kindle Store and the print Books store have separate category trees, so look at the one that matches the format you’re setting up. KDP’s own tip here is a good one: research your genre, see where similar books are categorized, and decide whether your book truly fits there.

Step 4: Balance Popularity and Relevance

This is the step where a little judgment comes in. You want categories that are popular enough to have real readers browsing them, but not so broad that your book gets lost among thousands of titles.

A simple way to check this is to open a category’s bestseller list and look at a few books near the top and a few further down. Click into them and note their overall Best Sellers Rank. If even the books lower on the list are selling very well, that shelf is quite competitive. If the rankings are more modest, a new book has a more realistic chance of being seen there.

Most importantly, every category you choose should accurately describe your book. Amazon is clear that it doesn’t allow categorization that misleads readers, and it may move a book out of a category that doesn’t match its content. A category that’s slightly less popular but a true fit will serve you far better than one that’s easy to rank in but doesn’t match what’s inside your book.

Step 5: Pick a Mix for Your Three Slots

Once you have a short list, I like to think about the three slots as a team that works together:

• One core category that describes your book’s main subject most directly.
• One more specific category where your book has a stronger chance of standing out.
• One category that reflects a second angle of your book, such as the reader it serves or a theme that runs through it, as long as it’s still an honest fit.

This isn’t a strict formula, and your book may call for a different mix. The goal is simply to avoid putting all three slots into one crowded shelf, so your book has a few different ways to be found.

Step 6: Add Your Categories in KDP (and Revisit Them Later)

When you’re ready, here’s how to add or update your categories, following KDP’s own instructions:

1. Go to your KDP Bookshelf.
2. Click the three dots (ellipsis) next to your book and select Edit details.
3. On the Details tab, review your Primary Audience and Primary Marketplace first.
4. In the Categories section, select Choose categories (or Edit categories if you already have some).
5. Click through to the category, subcategory and placement you want. If you already have three selected, remove one before adding a new one.
6. Save your changes and submit your book.

It can take up to 72 hours for your book to show up in its new categories, so don’t worry if you don’t see the change right away.

And please don’t think of this as a one-time decision. Your categories can be updated whenever you need to. If your book has been out for a few months and sales have slowed, revisiting your categories is a gentle, low-risk place to start. If you haven’t set up your book on KDP yet, my step-by-step guide on how to publish a book on Amazon KDP walks you through every screen, including this one.

Common Category Mistakes First-Time Authors Make

These come up often, and every one of them is easy to fix once you know about it.

• Choosing only broad categories. Shelves like “Self-Help” or “Business” are very crowded. Drilling down to more specific subcategories usually gives your book a better chance to be seen.
• Choosing a category just because it looks easy. It’s tempting to pick a small category that doesn’t really fit, but Amazon may remove or change categories that don’t match your book, and readers on that shelf won’t be looking for what you wrote.
• Assuming ebook and paperback categories are the same. They’re chosen separately and the options can differ, so check each format.
• Setting them once and forgetting about them. Amazon updates its categories from time to time, and your book may fit new shelves as it finds its readers. A quick check every few months is a good habit.
• Expecting categories to do all the work. Categories help readers find your book, but your cover, title and description are what turn a browser into a buyer. My post on how to write a book description that sells can help with that next piece.

How Categories and Keywords Work Together

Your categories and your seven keyword slots are partners. Categories place your book on the right shelves, and keywords help Amazon match your book to the specific phrases readers type into the search bar. KDP even suggests that if you can’t find a category that fits your book exactly, your keywords can help Amazon understand where your book belongs.

So once you’ve chosen your categories, it’s worth giving your keywords the same care. I cover that in detail in my Amazon book SEO guide, and if you’re thinking about your launch as a whole, my book marketing strategy framework shows how categories and keywords fit into the bigger plan.

Would You Like Help Choosing Your Categories?

If you’ve read this far and you’re thinking, “I understand it now, but I’d really like someone to do the research with me,” that’s exactly what my Amazon KDP Keyword & Category Research service is for. We start with a 30-minute call about your book’s main ideas and your target reader, and then I research keywords and categories based on your book, your audience and your competition. You’ll get specific recommendations you can use when setting up or updating your book on KDP, with up to three category recommendations for each format. Packages start at $297.

See the Amazon Keyword & Category Research Packages

Get My Free Guide Before You Publish

If you’re still getting ready to publish, start with my free guide, 5 Must Know Secrets Before Publishing To Amazon. It walks you through the things I most want first-time authors to know before they set up their book on Amazon, so you can go into KDP feeling prepared.

Download the 5 Must Know Secrets Before Publishing To Amazon

Have you already chosen your categories, or are you still deciding between a few? Share them in the comments. I read every one, and I’m happy to help you think it through.