I’d like access to a less accurate word count. No, really, this will make sense in a minute.
A full explanation of what I mean is conveniently posted on the Science Fiction Writers of America website, but the short version is that publishers aren’t interested so much in exact word count as in the amount of page space you’re going to take up. This consideration makes a two-word bit of dialogue that has to be set on its own line “worth” as many words as a sentence that runs from margin to margin. To account for this, we’re asked to do some calculating when putting the “approximately XXX words” number at the top of the first page when submitting a ms to publications. You figure an average number of words per line, you multiply it by the number of lines in a page, multiply that by the number of pages, and viola.
Could Scrivener do that? Using some basic formula, and the manuscript-outputting format specified in the Compile Manuscript window, track the approximate count of all files with the “include in manuscript” box checked?
Yes, you can do that in the final compile. There isn’t an approximation function in any of the built-in statistic panels, but you can include a word count on the cover page with the <$wc> token. There are several rounding functions you can use, such as <$wc1000> which rounds off to the nearest thousand words. To see all of the options use the Edit/Insert/Draft Word Count sub-menu. The value used to calculate will be whatever the current compile configuration is set to. So everything set to “Include in Draft” and also within the scope of the current compile group as well (which you can set at the top of the first tab in Compile).
The other thing to do is use View > Statistics > Project Statistics. The “paperback page count” gives a page count based on the idea of six characters being a word (five characters and a space), and 350 words-per-page (which is set via the Options pane, so you could change it to one-word-per-page to change it into a word count based on six characters-per-word). This is an old typography rule of thumb.
But all-in-all I think the word count rounded to the nearest hundred words is the best option (the one Ioa mentions that can be inserted in Compile). Most publishers are accustomed to receiving word processor word counts these days anyway.