Creating a search utility that would allow someone to find the word count for a particular book has proved challenging. Both goodreads.com and amazon.com offer services that allow programmers to pull book data, such as Title, Author, Number of Pages, etc.; But neither offers word count. So what we did, using the GoodReads' API, is create an algorithm using a book's page count, associated genres (including the order of those genres), and published date to come up with an approximate word count.
Is it perfect? Let's take a look at few examples. The actual word count for Harry Potter and the Sorcerer's Stone is 78,792 and our utility calculates 80,960, which is quite respectable. Twilight has a word count of 118,975 and our utility calculates it at 120,516. Not too shabby! Of course, The Da Vinci Code has a word count of 138,952 and our utility comes up with 129,870. So it'll certainly be off on occasion, but it's pretty close for the average book.
And if you're just looking for a few examples from a particular genre, the word counts for other books listed on this site have been verified. Word Count Ranges by Genre is a good place to start.
Once upon a time Amazon offered "text stats" for a majority of their books, which included word count. Although Amazon stopped offering this for new books several years ago, the feature still remained for older books. So, hey, at least we have it for most books, right? Well ... within the past few months, Amazon has removed that feature completely from it's website. I suppose it just wasn't as important as the Amazon Echo.
AR Book Finder is a great resource for writers, despite the fact that we're not actually the target audience. If you've never visited the site, you'll be asked if you're a Student, Parent, Teacher or Librarian when first arriving. I consider myself a student of life, so I selected student and continued on. I suspect you're a student of life too, so perhaps you should choose the same. From this point, search for your book, click on the title within the list of results, and on the following page you'll find the book's word count. Yay! Unfortunately they don't have all books, but they do have the most popular ones. So we got that going for us; which is nice.