Track everything closely for a week or two using one of the calories burned methods. If you are inline with your weight loss goals, GREAT! Keep using that method. If not, you might need to adjust the calories burned a bit. Either identify a method that seems closer to what you need -- more calories burned if you don't lose enough, or less calories burned if you're losing too quickly.
Spark People estimates have always worked good for me. I assume they work good for most! They are however estimates.
One BIG caveat. If you're eating healthy -- balancing carbs,fat, and protein; getting some fiber; eating some fruits and veggies; you know -- and you're still too hungry, you need to eat more. You DEFINITELY wouldn't want to eat less! Listen to your body! I assure you that craving to eat the whole chocolate cake is your mind not your body, but within reason.