Book Report includes estimated borrow numbers. Put simply: The estimated number of borrows is the smallest possible number of borrows that could result in the given number of page reads.
Kindle Unlimited allows readers to borrow books, but the number of times a book has been borrowed is not reported to authors. Book Report estimates borrows based on two other values: The number of page reads a book has received, and the number of pages in that book.
The estimated borrow count is the number of page reads a book has received, divided by the number of pages in that book. If a book is 200 pages long and has received 10,000 page reads, Book Report will estimate the book has been borrowed 50 times. 10,000/200 = 50.
Because each borrow can at most result in 100% of the pages being read, the estimate the lower bound on how many people actually downloaded the book through Kindle Unlimited. The actual number of borrows is higher than the number estimated.
Further details
- To access your borrow estimates, edit the Details section by clicking the pencil at the top right. Include the ~Borrows column.
- If you just started using Book Report and the estimates are way off, give it some time. The KENPC crawl takes some time. Wait for the spinner in the top left to disappear.
- Book Report uses the official Kindle Edition Normalized Page Count (KENPC) for these estimates.
- Once a week, Book Report will confirm the KENPC for each of your books. If it changes, the borrow estimate will use the new value from that date forward, but continue using the old value for page reads from before that date.
- By default, one estimated borrow means the number of page reads equals the KENPC, but the average borrower probably doesn't read 100% of the book. So on the Settings tab, you can set a different value for "What percent of KENPC counts as an estimated borrow?" If you set it to 50%, then 10,000 page reads on a 200 page book would result in 100 estimated borrows. That is because it assumes each borrow resulted in 100 (50% of the KENPC) page reads.
- Book Report doesn't do any of the estimations or calculations for data from before July 1st, 2015. Before that date KDP provided authors with their borrow numbers and Book Report still displays those numbers directly.