Calorie Goal Confusion

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It seems that MFP calculates the number of calories you burn based on just being alive, reduces that amount by 500 calories per day and calls the result Calorie Goal. In theory, that should result in a 1 pound loss per week (500 x 7 = 3500). But what if your goal is 2 pounds?

It seems MFP won't reduce calories by more than 500 regardless of the per week weight loss goal you set up in your Profile. In addition, it appears that any calories expended from exercise are added to your daily goal so any calories lost to exercise would then be replaced by eating. So how the heck can you ever figure out how many calories to eat to lose 2 pounds per week? If they don't think 2 pounds is a reasonable amount, why is that an option at all?

I'm a newbie here, so be gentle with my dumb question!