ATL I like to look at the whole picture. BMR+TEF+NEAT+Exercise to give you a decent idea of the calories out a person will have in a given day. And if you take in more than that consistently you are going to gain weight. Plain and simple.
I also think its OK to go over some days and under others because over time it should balance out. Its when you take in too much day after day that it becomes a problem.
I try to eat less on days I do not exercise because for one I am usually not as hungry and two I know I didnt burn that extra couple hundred calories in the gym.