calories in vs calories out,working out all these calculations are pretty useless though,what you need to do is change your current diet,cos if you have been eating roughly 2500 calories and a calculator tells you that you need 2900 calories to loose fat,by adding in calories you will end up gaining not loosing...
to put yourself in a defecit add in cardio and add in extra sets before you start cutting down calories,rather work and burn the calories off vs starve them off...