How Long Should a Science Fiction Novel Be, on Average?

How long should my science fiction novel be? What’s the shortest it can be—and the longest? What’s the average length for this genre? How long is too long for a sci-fi novel? And should I be counting by pages or by words?

These are common questions among first-time novel writers, and for obvious reasons. As a new writer, you want to do everything you can to increase the chance of getting your novel published someday. That includes following the norms and conventions regarding length.

So, h...