There is no universal word count for every book. A focused guide, devotional, memoir and illustrated children’s book each have different reader expectations. Review recent comparable titles in your category and note both their length and how they use chapters, images and supporting material.
Estimate a range, then divide it across the outline. If the number makes a chapter feel padded or rushed, revisit the structure. Your manuscript’s purpose is more important than a round total; clear writing and a well-planned reading experience matter more than adding pages.