How much are you trying to tell in your chapters? How much do you need to get done? How long do each of these parts of the chapter need to be?
When trying to decide if your chapter is long or short enough, those are the questions you need to ask yourself. It's okay to have short chapters, as long as you get done what you need to get done. As long as you can get the necessary character growth and development of the plot into each chapter.
I wrote a novella for a contest back in November. It couldn't be any longer than 20,000 words, and I needed twelve chapters for each of the needed events to happen. So before I started writing, I planned out approximately how long I wanted each chapter to be. I planned for the story to be 18,000 words.
It ended up almost hitting the maximum. My chapters varied length - from less than a thousand words to three thousand. And that's because that's how long they needed to be.
There is no minimum length for a chapter. Or a maximum length. It's entirely up to you and your story. Especially your story. And as you write more, you'll discover your chapters growing longer. When I first started seriously writing I was about ten years old and my chapters were less than five hundred words long. But I was writing on a fanfiction website that said to publish the story on it, it had to be at least a thousand words altogether. So I published multiple short chapters and my story got accepted.
The point is, after that, I gave myself a minimum length I wanted a chapter to be in a novel. It had to be at least a thousand words, and I hoped most of them would end up around fifteen hundred words. Guess how long my chapters ended up? A thousand words. Guess what they consisted of? Filler, to get even that far. Because back then, I didn't have enough to say, and when I did, I didn't know how to say it. I could have easily made some of the important scenes a couple thousand words if I was more experienced, and taken out the scenes and chapters where they sat around discussing expired potato chips. (For some reason I found that scene hilarious at the time. *shrugs*)
Let's bring back the example of the novella. It's the first story I've ever completed, so it's not that good, but that doesn't matter here. What matters is I had a word count maximum. Therefore, too many of my scenes were rushed, because I didn't have the space to say what needed to be said. But there were some scenes I let be as long as they needed to be, and some of those chapters are short. But they're not as rushed as the others.
Now, other than that novella, my chapters are at least two thousand words, and many times even longer, up to five or six thousand words. Because I know how long it takes to say what needs to be said, and I take that time to do so. I'm not saying my scenes aren't still rushed (I'm working on that), but I know they shouldn't be shorter because I'm lazy, or longer so I have more to be proud of.
I've talked about what happens if your chapters are too long and if they are too short. Let's go back to the latter.
I'm going to be crazy and say it's okay to add filler. Your heroes can't be running around chasing villains all the time. Sometimes they need a break. But do not add too much of this. If you add this kind of filler at the end of every chapter your story will feel episodic. Do not add filler unless it's necessary - and not necessary to your word count. If filler is necessary to your story, add it. But then again, it wouldn't be considered filler anymore if it's needed, would it?
I've said this quite a few times, but it bears repeating. Do not rush through your scenes. Let what's needed to be said said, and what's needed to be done done. Let them run their course. It's okay if they're not as long as you think they should be. They will grow as you grow as a writer. Unless they need to be short. Then they will be short and everyone will be happy.
I still try to keep my chapters over a thousand words, and usually even over two thousand. Because if there isn't enough meat to get it that far, does it really belong as a chapter in your story? Maybe as a scene, but is it really necessary to be a chapter? It's okay to put chapters together if they work better that way.
