The JavaScript Editing Project Calculator calculates the number of hours (and days) to edit a specified number of pages.
This calculator is based on the calculator provided by Peter Kleczka, which I can no longer locate on the Internet, unfortunately.
His calculator was based the Dr. Joann Hackos' book, Managing Your Documentation Projects, and a Java based calculator she had previously posted on her Web site: http://www.comtech-serv.com/dependency_calculator.htm.