I began my obsession with word counts a couple of weeks ago, at the beginning of writing a short story. I was 3,000 words into the first section and already wondering if the final draft would be too long to be published in a journal before I was finished with the thing. That, coupled with a new account on Pinterest, led me to create a Word Count Chart (which, FYI, I also pinned there on my Writers Tools and Tips board.)
Of course, there is no rigid definition of either a short story or a novel. I made the chart to get a general idea of what territory I was in—flash, novella, etc. But once you're ready to look for a publisher, it's best to know what your potential market wants: each literary magazine may have a different definition of the short story along with a suggested word count.
And those definitions may vary for special issues or occasions. For example, Glitter Train, which publishes only fiction, has a wide word count—"2,000 to 20,000 words"—for its Fiction Open. But they also have a Very Short Fiction Award for "up to 3,000 words."
I know of no short cut for finding a journal looking for a particular word count—but you can find journals according to genre through the Poets and Writers Literary Magazines database, and then link to individual journals to check their writers' guidelines.