Author Desk is a set of free tools for authors and small publishers. The calculators work out KDP cover and spine sizes, printing costs, royalties, ISBN costs, and the fees Etsy and Gumroad take from a digital sale. The time tools estimate how long a text takes to read or say and how long an audiobook runs. The EPUB tools open, check, edit and build EPUB files. Nothing you type or open is uploaded.
How to choose: start with what you are making. For a printed book, use the KDP cover and print-cost calculators and the ISBN tools. To see what you keep from a sale, use the royalty and fee calculators. To time a manuscript, a speech or an audiobook, use the reading and audiobook time tools. To read, check or build an eBook file, use the EPUB tools. Platform fees and rules change, so every page shows the date its figures were checked and the page they came from. Results are calculated from the numbers you enter; they are not tax, legal or pricing advice.