My own rule of thumb on chapter breaks are at changes of scene/time or character perspective. It gives the reader a logical break to switch mental gears, to pick up the story at a different point in time, a new location, or where the narrative jumps to something new. I find changing character perspectives in the middle of a chapter is distracting.

I don't follow the rule all the time. A good story has to entertain first, not win an A for mindless adherence to rules of composition.