Book Math Tools

Kindle Box Set Price Calculator

Enter your series and a box set price to see the reader's discount, what each box set sale earns against selling the books separately, and what a full Kindle Unlimited read pays.

Reader saves
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Royalty per box set
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Royalty if bought separately
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Box set keeps
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Full KU read: box set
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Full KU reads: separately
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How the comparison works

box royalty = 0.70 × (box price − VAT − delivery), or 0.35 × (box price − VAT) outside the 70% band
separate royalty = books × royalty of one book (file size split evenly)
KU box set read = min(books × KENPC, 3,000) × rate

"Box set keeps" is the box set royalty as a share of what the same reader would pay you buying every book. The single-book file size is the box set's divided by the number of books, which is close enough for text.

Worked example: five books at $4.99

A five-book series sells at $4.99 each, $3.39 royalty per book, or $16.95 if a reader buys all five. The 5 MB box set on Amazon.com:

Box priceReader savesRoyalty optionRoyaltyShare of separate
$9.9960%70%$6.4738%
$12.9948%70%$8.5751%
$14.9940%35%$5.2531%

The jump from $12.99 to $14.99 costs $3.32 per sale, because it leaves the 70% band. On Amazon.com, $12.99 is the most a box set can earn per copy.

Worked example: a ten-book collection in Kindle Unlimited

Ten books of 400 KENP each add up to 4,000 pages, but KDP pays a KU reader's box set read up to 3,000 pages. At $0.0045 a page, a full read of the box set pays $13.50, while the same reader borrowing all ten books would pay $18.00. Smaller sets stay under the cap: a trilogy of 420-page books is 1,260 KENP, so the box set and the singles pay the same $5.67 for a full read, and the $7.99 box set sale earns $5.28 against $8.07 for three separate sales.

When a box set makes sense

A box set earns less per reader than selling the books one at a time; its job is to reach readers who wouldn't have bought book 1 at full price, and to get a completed series in front of binge readers. That makes it most useful once a series is finished and the first book's sales have slowed. Keep the price inside the 70% band, watch the file size if the books have images, and if your series runs past 3,000 KENP in total, consider two smaller sets (books 1-3 and 4-6) so KU reads aren't capped. To see what each new series reader is worth, use the series read-through calculator.

Frequently asked questions

Why does my box set earn less at a higher price?

Because the 70% royalty stops at the top of the band: $12.99 on Amazon.com, £12.99 on Amazon.co.uk, €12.99 in the euro stores and A$15.99 in Australia. A $14.99 box set pays 35%, which is less per copy than the same set at $9.99 on 70%.

How do Kindle Unlimited reads work for a box set?

KDP pays for at most 3,000 KENP per title per customer. A box set is one title, so if the books add up to more than 3,000 pages, a KU reader who reads all of it earns you less than if they had borrowed each book separately.

Does KDP have rules for box sets?

Yes, for ebooks. KDP's Boxed and Bundles Edition Guidelines ask for a title that says it is a multi-book product (for example "Books 1-3" or "Boxed edition"), a description that says so in its opening paragraph and lists every included title, and disclosure if the books were published before. KDP also says it prefers individual titles linked in a series for discoverability.

Can the box set be in KDP Select while the single books are wide?

Check with KDP before you try. KDP Select requires the enrolled ebook to be exclusive to the Kindle Store, and a box set contains the same text as the single books, so if the singles are sold as ebooks on other stores the box set's content is not exclusive. The KDP Select vs wide calculator helps decide which way the whole series should go.

Sources

Rates last checked against KDP's help pages on 2026-10-16.

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