Planner of pantser, I do both depending on the work, a chapter for me is not about word count, but the scenes that are in it.
I make sure each scene has a point to it, has a beginning-middle-end, and has a plot point to move the story forward to the next scene. Word count is irrelevant when constructing a scene. Just like in a play, they need to build up to a point or carry something through to the next plot point.
Writers who read plays learn about this device and put it to use. Next time you're at the library, look for books on writing plays.
My other device is having 1-2 plot points per chapter, which can mean 1-2 scenes. If it is an especially important scene, that will get its own chapter. I've had them running long and short, but so long as they run.
It's all tied in with the pacing of a work. I'm apparently good at it, having gotten complaints that a 50K word work was not a novel but a short story. All it means is the reader couldn't put the book down. We all want that!