Understand your KU earnings
In Kindle Unlimited, you're not paid per borrow — you're paid per page read, measured in KENP (Kindle Edition Normalized Pages). Each month Amazon sets a per-page rate from the global KDP Select fund (recently around $0.0045). Enter your book's KENP count and how many full reads you expect to estimate your monthly page-read royalty.
This is an estimate — the actual rate changes monthly, and real readers don't all finish, so treat it as a planning guide.