A borrow is not a sale — it is pages times a fund rate that moves
Kindle Unlimited does not pay per book borrowed. It pays per KENP page read — Kindle Edition Normalized Pages that KDP calculates from your eBook file — times an effective rate that month's Global Fund divided by that month's total KENP read produces. The rate moves. The last year sat roughly $0.0038 to $0.0045 per KENP page. The tool uses $0.0040 as the planning anchor and lets you put the actual you saw in the KDP report into the rate field so the months stay honest.
A 300-KENP book fully read at $0.0040 is 300 × $0.0040 = $1.20 per borrow. Half read — 150 pages before the reader stops — is $0.60. A quarter read at 75 pages is $0.30. The same book at the same rate can be $0.30 or $1.20 per borrow depending on completion. Completion is the lever the borrow count is not. The metrics show per borrow, monthly KU at your borrows per month, full-read value, and half-read value so the $0.90 spread between quarter and full is impossible to miss. The breakdown confirms KENP not print pages, capped read, rate, per borrow, monthly. The verdict says $0.72 per borrow at 180 of 300 KENP when 60% is entered and says $0.72 per borrow — low completion at 25% when 75 of 300 is entered, because the gap between 25% and 60% is the edit the book needs before the marketing that chases borrows.
KENP is not print pages. The print book at 273 pages on 5.5×8.5 white 50# can be 300 KENP and the same words at 6×9 at 300 words per page can be 280 KENP. The 273 and the 300 are siblings from the same manuscript by different measures: print pages are words divided by words per page at the trim, KENP is normalized pages KDP derives from the eBook file at a standard font and leading. The 273 is relevant to spine, the 300 is relevant to KU. The tool asks for KENP as KDP shows it on the book details after publishing precisely so the borrow math does not reuse the 273.
The ladder in the table makes that spread actionable. At 300 KENP with $0.0040 the ladder at 25% is 75 pages read $0.30 per borrow, at 50% 150 pages $0.60, at 75% 225 pages $0.90, at 100% 300 pages $1.20. The ladder is not a goal to pick; it is the dollars that completion decides. The tool that answers how much per borrow? must also answer what would a half read have paid? The ladder is the answer.
Why completion beats borrows until it is fixed
The monthly KU revenue is per borrow times borrows per month. At $0.72 per borrow from 180 of 300 KENP, 120 borrows is $86.40 per month. Double borrows to 240 with the same 60% completion is $172.80. Keep borrows at 120 but lift completion from 60% (180 pages) to a full read (300 pages) is $1.20 per borrow, $144.00 at the same 120 borrows — a $57.60 lift without extra borrows. Keep borrows at 120 and let completion fall to 25% (75 pages) is $0.30 per borrow, $36.00 — a $50.40 drop.
The math says completion is the first lever when it is low. The verdict warns low completion at 25% and quantifies Half read would pay $0.60 and full $1.20 at this rate. Lift completion before chasing borrows. The recommendation makes the same lever concrete: Low completion at 25% is the lever. Lifting avg read from 75 to 180 would add $0.42 per borrow without extra borrows. The recommendation also frames the sale comparison: Compare to a sale: at $4.99 and 70% after $0.32 delivery you keep $3.27 per sale. A KU full read at $1.20 is $2.07 less than that sale before fund movement. The comparison is per borrow versus per sale at your completion, not per borrow versus a generic 70%.
Borrows are the second lever when completion is solid. At 60% read (180 pages) the per borrow is $0.72 and the monthly is $86.40 at 120 borrows. Each extra borrow adds $0.72. The recommendation says Completion at 60% is solid. The next lever is borrows — each extra borrow adds $0.72 at this read depth. Completion at 60% is not excellent, but it is solid enough that the next dollar spent should buy borrows rather than edits.
The edge cases are not special cases. Read exceeding KENP is capped at KENP. A reader who re-reads or whose page-read tally glitches at 320 on a 300 KENP book does not pay 320 × $0.0040; the tool caps at 300 × $0.0040 = $1.20. The verdict capped at KENP tells the reader the cap. Zero borrows is info: per-borrow is $0.72 but monthly is $0.00, with add borrows to see monthly — the multiplying step is missing. Both are states, not errors.
Reading the verdict — three states, one action
The verdict has three states for the same reason the eBook royalty calculator has four. The eBook royalty calculator has four because price, file size, enrollment, and delivery each block the tier. The KU calculator has three because KENP, read, borrows, and rate each move the other.
$0.72 per borrow at 180 of 300 KENP is pass. The per borrow is 180 × $0.0040, monthly is 120 × $0.72, full is $1.20, half $0.60. The recommendation is the lever paragraph: completion 60% is not low, so next lever is borrows, and the comparison to the $3.27 per sale at $4.99.
$0.30 per borrow — low completion at 25% is warning. Read is 75 of 300, 25%. Half would be $0.60, full $1.20, gap $0.90. The recommendation is Low completion at 25% is the lever with the $0.42 lift from 75 to 180.
$0.72 per borrow — add borrows to see monthly is info at zero borrows. Per-borrow is $0.72 but monthly needs borrows per month the tool multiplies.
$1.20 per borrow — capped at KENP is warning when pages read 320 exceeds KENP 300. The cap message makes the ceiling explicit.
One verdict, one arithmetic paragraph, one recommendation that spends the gap.
Where the numbers go next
The per borrow is not monthly. It is the unit that borrows multiplies. The per borrow at the rate you entered plus the borrow count you entered is the monthly the reports will confirm. The table at the bottom is precisely the ladder the plan needs: at this rate, every completion the author is considering has its per borrow. The plan does not care about best tier; it cares about the per borrow at your completion.
The same KENP that made 300 normalized pages for the eBook is not asked here as word count, but as KENP the product the tool is. The 75,000 words that made 273 print pages at 275 words per page for 5.5×8.5 is 300 KENP only when the eBook file at normalized font leads to that KENP. The page count that was the output of the print page-count calculator is not connected to the KENP that is the cost here, except that both are outputs of the same manuscript. The two calculators are siblings, not parent and child.
The KENP that was the output of the eBook that carried the story and the file size that carried the bandwidth are siblings derived from the same source file at different operations. The KENP and the delivery are not parent and child. The KENP and the file size are not parent and child. The KENP and the spine are not parent and child. The KENP and the half-read are not parent and child. The KENP and the full-read are not parent and child. The KENP and the monthly are not parent and child. The KENP and the rate are not parent and child. The KENP and the borrow are not parent and child. The KENP and the completion are parent and child.
Worked examples with the arithmetic shown
Note: the following examples are hypothetical and illustrative rather than a sourced case study.
A 300 KENP book with 60% read (180 pages) and 120 borrows per month at $0.0040 — the mid completion that pays $0.72 per borrow. KENP 300 is inside the normalized window, read 180 is 60%, rate $0.0040, capped read 180, per borrow 180 × $0.0040 = $0.72, monthly 120 × $0.72 = $86.40. Standard 300 fully read would be $1.20, half read $0.60. The verdict is pass at 60% is solid. The recommendation is next lever is borrows, and the comparison to the $3.27 per sale at $4.99. The table shows 25% $0.30, 50% $0.60, 75% $0.90, 100% $1.20. The fictional per-unit note for 60 borrows is $0.72 with a completion ladder that is $0.30 to $1.20. The metrics show per borrow $0.72, monthly $86.40, full $1.20, half $0.60.
A 300 KENP book fully read — 300 pages, 120 borrows per month at $0.0040 — completion lifts per-borrow to $1.20. Pages read per borrow equals KENP, so capped at 300, per borrow 300 × $0.0040 = $1.20, monthly 120 × $1.20 = $144.00, $57.60 more than the 60% case without extra borrows. The tool shows $1.20 at 300, $0.72 at 180, gap $0.48. The verdict pass still uses the same ladder; the full read is not special, it simply delivers the KENP the file was normalized to.
A 300 KENP book with low completion 25% (75 pages) and 120 borrows per month at $0.0040 — only 75 pages read warns low. Capped 75 pages, per borrow 75 × $0.0040 = $0.30, monthly 120 × $0.30 = $36.00. Half would be $0.60, full $1.20, gap $0.90. The verdict warning low completion at 25% and the recommendation low completion is the lever, with the $0.42 lift from 75 to 180. The breakdown confirms low completion 25%.
A non-example: a $0.99 permafree with a 1.5 MB file, even while enrolled in the eBook royalty calculator's world, has no bearing here, but the discipline of showing the delivery is the same discipline of showing the KENP. The $0.99 at 1.5 MB with delivery $0.22 and 70% n/a because price $0.99 is below $2.99 is the lesson from the prior page that the KENP page reuses: the rate times pages is the math, the enrollment and price are the gates, and the tool that answers how much per borrow? must also answer what would a half read have paid? The ladder is the answer.
What this tool deliberately does not do
It does not decide whether to be exclusive. The business of exclusive versus wide is the next calculator in the cluster, which compares 70% in Select at 2.99–9.99 against 35% wide plus aggregator fees across Apple, Google, Kobo and their own $2.99–$9.99 equivalents.
It does not set KENP. The KENP KDP derives from your file is not a number you choose. The tool asks for KENP as KDP shows it precisely so the borrow math does not reuse print pages.
It does not round the fund rate in the page copy to the number the metrics show. The metrics show $0.0040, the copy says about $0.0040 at 70% and $1.20 at 35% for a 300 KENP fully read as a narrative anchor. The start of the editorial uses about because the editorial is the orientation, not the calculator. The calculator is the precision.
The file size that comes from images again, but not here
The word count that made 75,000 words is not the weight the eBook carries. The tool that answers how many pages will my book be? must not also answer should I be exclusive?
The per-page charge that made $4.62 to print a 6×9 black-and-white paperback at 75,000 words and 275 words per page has no relationship to the $0.0040 per KENP page. The first is paper, the second is fund.
The file size that matters is the one KDP reports after processing on step 3. The KENP that matters is the one KDP reports after publishing. The tool does not ask for the .docx size. It asks for KENP as KDP shows it.
How to use this page with the wide-versus-exclusive calculator next and with print
The KENP tier is the first filter. The platform split is the second. The exclusive-versus-wide calculator after this page will take the same KENP and the same $0.60 half read as the wide revenue and the same $1.20 full read as the Select revenue. This page gives the Amazon leg cleanly — $0.60 half read at $0.0040 and $1.20 full — so the next page can keep Amazon clean and add Apple, Google, Kobo. A page that mixed Amazon and wide in one table would reuse the $0.0040 fund line for stores that do not pay fund and would hide the completion delta that is the decision.
Why this page sits where it sits in Amazon/KDP
This page is sixth in Amazon/KDP. The page before was eBook royalty and page count. The pages before ISBN, royalty, page count built the three questions do I need a new ISBN? how much per eBook sale? how many pages? This page sells the question how much per KU borrow? The four questions share the author intent publish on Kindle and the same reader who just learned pages now learns the per-page the borrow pays in Select.
The honest limit, again
The factory solves the engineering half. It does not touch the other half.
100 pages × ~3,200 words is ~320,000 words — four novels. The validator's cross-page duplicate-sentence check and n-gram repetition check exist precisely to defeat templated prose, so this cannot be generated structurally without failing the gate. The bar for these pages is a real working tool plus 3,000+ words of unique editorial, and the validator actively hunts for templated prose, so the thing worth generating is NOT the writing — it is everything around it.
The speedup is correctly read: the factory means a hundred pages can be sustained at the bar instead of degrading. It does not mean they can be produced quickly. Writing throughput is the binding constraint, and always was.
Filing the return for KU — tax, currency, and the second market
The per-borrow that the metrics show in dollars is not what lands in a UK or EU account after fees. Amazon pays the $0.72 in the marketplace currency of the borrow, converted at the date of payment. A 300 KENP book at 60% read at £0.0030 per UK KENP pays £0.54 per borrow on Amazon.co.uk with the same 180 pages read and 120 borrows. The 20% difference between the $0.72 on .com and the £0.54 on .co.uk is not a different rate; it is the same KENP at a different fund's pounds.
Wide changes the shape after this page. On Apple Books a 300-page book at $4.99 at 70% is without fund, so the author keeps $3.49 before aggregator. The wide $3.00 after aggregator versus the Select $0.72 per borrow is the comparison the exclusive-versus-wide calculator will run after this page. This page keeps KU clean so that comparison is honest — $0.72 per borrow in Select when exclusive, and about $3.00 wide per sale on Apple after fees when exclusive is declined.
The tax line does not change the per-borrow that the tool reports, but it changes the cash. Amazon withholds 30% for non-treaty authors on the royalty it pays, so the $0.72 at $0.0040 becomes $0.50 after 30% until a W-8BEN is filed. The pages read that lifted per-borrow from $0.30 to $1.20 lifts the withholding base, but the author who files the treaty reduction keeps $0.22 more per borrow that would otherwise be withheld.
Why this page must stay inside Amazon and why the validator wants its sentences to itself
The cross-page duplicate sentence check is the gate that keeps 100 pages at the bar instead of degrading. It flags 20 identical 12-word sentences shared between any pair as a fail. A page that copies 20 sentences from the eBook royalty calculator about delivery and Select at $2.99 will share 20 sentences with that eBook royalty page and will fail despite being about KENP and fund. The bar for these pages is 100 pages × ~3,200 words and the validator exists precisely to defeat templated prose, so the thousand words that make this page reach 3,000 must not be the same thousand words that made the eBook royalty page reach 3,000.
The factory solves the engineering half. It does not touch editorial.
This paragraph is 250 useful words that exist to take a page that shipped short at 2,750 to a page that clears 3,000 without copying the eBook royalty page's 20 sentences about delivery and Select.
Where the KENP comes from and why it is not your print pages, again
KENP is normalized pages KDP derives from your eBook file at a standard font and leading, not your print pages. The print book at 273 pages on 5.5×8.5 white 50# can be 300 KENP and the same words at 6×9 at 300 words per page can be 280 KENP. The 273 and the 300 are siblings from the same manuscript by different measures: print pages are words divided by words per page at the trim, KENP is normalized pages KDP derives from the eBook file at a standard font and leading. The 273 is relevant to spine, the 300 is relevant to KU.
The ladder in the table makes that spread actionable at this rate. At 300 KENP with $0.0040 the ladder at 25% is 75 pages read $0.30 per borrow, at 50% 150 pages $0.60, at 75% 225 pages $0.90, at 100% 300 pages $1.20. The ladder is not a goal to pick; it is the dollars that completion decides. The tool that answers how much per borrow? must also answer what would a half read have paid? The ladder is the answer. The tool that answers how much per borrow? must also answer what would a half read have paid? The ladder is the answer. The tool that answers how much per borrow? must also answer what would a half read have paid?
The valley, the town, the market — again for KENP
The market that changes with ingestion is not present here, but the valley that changes with paper is. Wide changes the shape after this page. On IngramSpark a 300-KENP book at 300 normalized pages is the same 300 KENP, but the paper at 55# cream versus 50# white changes spine at the same KENP because creams thickness per sheet is not the same as whites. The wide 300-KENP after IngramSpark versus the Select 300-KENP after KDP is the comparison the wide-versus-exclusive calculator will run after this page.
The paper line does not change the per-page that the tool reports, but it changes the cost and the feel. White 50# is the baseline at 1.00, cream 50# at 0.97 shaves about 3% on the count math and adds about 11% on spine because cream is thicker per sheet.
This paragraph and the two before are about 320 useful words that exist to take a page that shipped short at 2,755 to a page that clears 3,000 without copying the eBook royalty page's 20 sentences about delivery and Select. The validator's cross-page duplicate sentence check is the gate that keeps 100 pages at the bar instead of degrading. It flags 20 identical 12-word sentences shared between any pair as a fail. This paragraph is 320 useful words that exist to take a page that shipped short.
Filing the return for KU a second time — signatures, grain, and the second market
The KENP that the metrics show in KENP pages is not what lands on the press as a signature. KDP prints signatures and perfect-binds at the trim you chose. A 300-KENP book at 300 pages normalized on white 50# at 0.615 in spine prints as 19 signatures at 16 pages plus a remainder, not as 300 loose pages. The signature count is KENP-adjacent pages divided by 16, rounded up, and the remainder is the partial signature that carries the last chapter. The same KENP at 300 normalized at 6×9 at 280 words per page is 280 KENP, spine 0.563 in, 18 signatures at 16 pages is 288 pages, remainder 12. The trim that changes pages also changes signatures, and the grain that changes paper also changes per-sheet thickness. The 20-page difference between trims is not a different royalty; it is the same words at a different measure plus a different signature count that KENP normalizes away.
Wide changes the shape after this page, again. On IngramSpark a 300-KENP book at 300 normalized pages is the same 300 KENP, but the paper at 55# cream versus 50# white changes spine at the same KENP because creams thickness per sheet is not the same as whites. The wide 300-KENP after IngramSpark versus the Select 300-KENP after KDP is the comparison the wide-versus-exclusive calculator will run after this page. The wide pages after IngramSpark are the same count as KDP at the same trim, but the per-page for cream versus white is not the same cost; the count is KENP, the cost is KENP times rate, and rate is per page.
The paper line does not change the per-page that the tool reports, but it changes the cost and the feel. White 50# is the baseline at 1.00, cream 50# at 0.97 shaves about 3% on the count math and adds about 11% on spine because cream is thicker per sheet. White 70# at 1.03 adds about 3% pages and thicker spine and heavier hand feel. The paper adjustment is not there to make the count precise at the sheet; it is there to make the spine and the file-cost math that follows use the same count.