A question that has come up in many discussion groups is, how long should a story be? Some stories barely breach the definition of a novel at 80,000 words while others could challenge Harry Potter for sheer heft. So then, what Is the right length? The short answer is that a story is only as long as it needs to be.
You have to go by the story itself. Is it a limited concept? Not too many characters involved, only one basic setting, with a short-reachcing goal? Then make it a novella, or even a short story if you have to. Or perhaps it involves several characters and a few different locales they travel around to. Maybe a plot that threatens the lives of one or more people or even a city. Well, then you have a full out novel pushing 130,000 words or better.
But what about something bigger? A truly epic scope with many characters, the world in jeopardy, and a villain that just won’t quite. then you might be thinking a really long one, or even an epic. Something that you’d have to tell in several novels in the series. The points, you do not choose the length, the story does. Never- and I mean *NEVER* decide up front “Hey, I’m going to write a 200,000 word book today”, or “I think I’ll keep this one down to 100,000 words to make it easier to sell”. The former decision results in fluff while with the latter one the story suffers from truncated scenes and unfulfilled promises.
Just simply start writing the story. Plan it out ahead of time, how many characters you need, how broad or narrow the story is, the world it’s in, and so on. then start writing. If it comes out to a novella, then that’s the right length. If it comes out to something far longer, then great. as long as it doesn’t read like someone’s trying to force it into a given length by either padding or truncating. When you can read it and not be thinking if it’s too long or is missing a few points then it’s perfect. If it’s an epic tale of some alien world, then you’ll be inserting a lot of descriptions of the vast alien lands which will increase the size as a result. But if it’s just taking place around one specific neighborhood then you won’t be needing that much room for such.
Write the story, not the market. Be not concerned with too long or too short to fit into some artificial niche which will only doom you to mediocrity, but instead concern yourself with the story. It will tell you when it’s done.