When I write my novels, I think of each chapter as an episode, or a little story within the bigger story, and a specific event occurs in each chapter. Let’s say your protagonist plans to meet up with another character, but then something unexpected happens. Maybe she has an accident on her way to the meeting and she’s rushed to the hospital. That would certainly be a little story within the bigger story. And since I like to have a strong ending to my chapters, I might end with the man she was supposed to meet thinking he’s been stood up. The next chapter would be a new episode about what he does next.
So, how long should a chapter be? Simple. It’s as long as it needs to be to tell the story. I’ve written chapters as short as a page and a half, and as long as ten pages. There really is no hard and fast rule for chapter length, at least not one that I’m aware of. So don’t worry about the page count; just concentrate on telling your story.