I charge per "indexable page.” “Indexable pages” include:
The per indexable page rate generally ranges between $4.25 and $5.00 and is dependent upon the following:
Most general trade books fall in to the $4.25 to $4.50 range. Most scholarly texts, $4.50 to $5.00. Most business documents, such as training manuals and annual reports, are in the $4.00 to $4.25 range.
The best way to determine your rate is to provide a sample chapter from the middle of your book (not an introduction or conclusion chapter) and to advise the number of indexable pages (I can help you determine that), and the due date. I can then review this information and provide you with a project quote so that you will know the full cost before committing to the job.