Is Kindle Unlimited worth it for your book? The per-page arithmetic

Kindle Unlimited is worth it for your book when borrowers read enough of it to replace the sales you give up elsewhere. In September 2026 a reader finishing a book with a 300-page KENPC earned the author about $1.61. A $4.99 sale on Amazon.com's 70% option earns $3.39. So each lost sale needs roughly two complete reads to break even, and the genres where that happens most reliably are romance, fantasy and mystery or thriller.

One thing changed in October: Amazon renamed Kindle Unlimited as Kindle+, as Written Word Media reported on 22 October 2026. Ebook reading is still paid by page from the same fund, so the arithmetic below holds. The new name is rolling out across marketplaces, and you will see both names for a while.

How the money is worked out

Books in Kindle Unlimited must be enrolled in KDP Select. Amazon sets a monthly KDP Select Global Fund, and each marketplace's share is divided by the total pages read there that month. KDP's help page on KENP states that formula and says the fund for each month is announced around the 15th of the following month.

Pages are counted in Kindle Edition Normalized Pages, or KENP. KDP lays the book out with standard font, line height and spacing, counts from the start reading location to the end, and includes images and charts. The result is the book's KENP page count, usually written KENPC, which several author guides say appears on the title's Promote and Advertise page in your Bookshelf once it is enrolled. Each page pays once per subscriber, and KDP caps it at 3,000 KENP per title per customer.

Amazon does not publish a per-page rate. Written Word Media calculates the US rate by dividing reported royalties by pages read, and its 2026 figures are below. The fund amounts are Amazon's.

A bigger fund does not mean a higher rate, because the rate also depends on how many pages subscribers read. July had the largest fund of the year and one of the lowest rates. Our article on the latest per-page rate tracks the monthly figures.

The arithmetic for a 300-page novel

Assume your novel has a KENPC of 300 and a 1 MB file, priced at $4.99 on Amazon.com. A sale on the 70% option earns 70% of $4.99 minus the $0.15 delivery fee, which is $3.39. A complete read at September's rate earns 300 × $0.005365, which is $1.61. At January's rate it was $1.26.

So one sale is worth about 632 pages read at September's rate, or about 806 at January's. That is between two and three full reads. Partial reads count, but they pay only for the pages turned, so a book that loses readers at chapter five earns far less than the full-read figure.

So compare the page reads with what you would sell if the book were not in Select. A subscriber who borrows your book might never have bought it, so a borrow is not the same thing as a lost sale. What you give up is everything outside Amazon: Apple Books, Kobo, Google Play, library platforms and your own website. If those channels would bring in more than the page reads, the book belongs wide.

Which genres do well, according to the trade sources

The sources agree on the broad pattern but the data is thin and some of it is old.

• Written Word Media's 2023 study found that 89% of the romance titles in Amazon's paid top 100 were in Kindle Unlimited, against 73% for fantasy, 73% for mystery and thriller and 64% across all genres. Its survey of over 3,000 readers found 35% of subscribers named romance as their main genre, compared with 25% of other readers. Non-subscribers read more horror, children's books and young adult fiction. The author called the chart check a one-day snapshot rather than a rigorous analysis.
• The Alliance of Independent Authors recommends going wide as its default. In the ALLi podcast episode on the question, author Adam Croft said non-fiction is not a big Kindle Unlimited market and that some fiction genres can earn more in it in the short term. That episode dates from 2019.
• Kindlepreneur, in a guide by Jason Hamilton updated on 1 October 2025, does not name genres. It says hyper-specific and emerging niches tend to do better in Kindle Unlimited, suggests checking how much of your category is enrolled, and recommends wide for authors aiming at a long full-time career.

Taken together, that points to Kindle Unlimited for series fiction in romance, fantasy and mystery, where subscribers read heavily and finish books. It points away from non-fiction, children's books and young adult, where readers buy rather than borrow or the audience is outside the subscription.

How to decide for one book

1. Check what share of the bestsellers in your category carry the Kindle Unlimited badge. A high share means subscribers are looking there.
2. Find your KENPC and multiply it by the latest US rate to get the value of a full read.
3. Divide your 70% royalty by that figure to see how many full reads replace one sale.
4. Estimate what the book would earn outside Amazon, including direct sales.
5. Enrol for one 90-day term if the numbers favour it, and switch off auto-renew if you want to review it at the end.

Our guide to deciding per book covers the wide side in more detail, and what Select exclusivity covers explains what you can still sell while a title is enrolled. If you take a book wide, the Indie Author Toolchest can sell the ebook direct from your own author page.