TDEE?

This website doesn't know what your body fat % is, or how active you are, or what you are doing. All it knows is that if you are dead set on extreme weight loss, that if you eat under 1200 calories for too long you will need to go to a hospital.

MFP does the least amount of math possible to give you a number. If you do the math yourself you are going to be much more likely to succeed.

I am 5'3" and I hardly ever eat less than 1800 calories. I have never had issues losing weight. I am still dropping. I ate 2100 calories on Saturday since I exercised off over 600 and didn't want to go under my BMR. I lost .2 lb.

You are going to lose weight at a super low amount of calories. But you are also going to stall, feel like crap, and then gain all the weight back. Then you'll be back on this website posting a new thread asking what you did wrong.

Just do it right the first time and save yourself the trouble.

So when you eat 1800, do you exercise? Or is that your base line like 1200 is for others?

My baseline, based on my TDEE-20% set to being "lightly active" is 1550. If I didn't exercise at all, I would lose weight if I ate 1550 calories.

Since I exercise different amounts every day, that is why I set my TDEE estimation at "lightly active". That means that if I exercise, I am now no longer at my estimated TDEE. My activity level is above it, so, I have to eat back all of those exercise calories in order to make sure my body is getting the 1550 it needs.

Now, I think my BMR is around 1300, which means I should never NET under 1300. However, I always try to keep my net as close to my TDEE-20% as I can, because I'm trying to stay as healthy as possible and eat as much as possible to still lose weight so that when I switch to maintenance it will be extremely easy to just eat a couple hundred more calories a day to maintain.

I know it's a lot to take in, but does that sort of make sense?

BMR: Least you should ever NET
NET: The amount of calories you have left after you subtract exercise
TDEE: I have mine set up on "lightly active" since I exercise different amounts ever day
TDEE -20%: That is the amount of calories that you can NET and still lose weight

Kind of? So since my BMR is ~1600, if I ate that, with NO exercise, I would still lose weight? I am 22, 180lbs, 5' 9''. My activity comes from school. It just seems kind of high.

I am a little confused as well about the BMR and the TDEE. I went to two different websites to calculate both and here is where I am confused....My BMR is 1503 my TDEE is 1796. If I were to eat 20 percent less than the TDEE it comes up as 1436 which is less than my BMR. So if I am supposed to eat at my BMR but 20 percent less of the TDEE is less than that how does that make sense. i am really wanting to try and make a real go at this and being my first time dieting I am really confused

Your TDEE must be calculated with what you normally spend in terms of energy in a day or averaged over a week. There are some calculators out there that will figure out in a more detailed fashion what you do daily in terms of activity and include the exercise you commit yourself to doing. The 20% reduction is based on that number so it must be accurate. And as said before, you should never eat below your BMR. That is just asking for trouble.

It really isn't that complicated.

Step one: Figure out your energy expenditure for the day. Use various calculators to get a number...it doesn't have to be super accurate. A few calories is not going to make a big difference.

Step two: Subtract 20% from that number.

Step three: Eat that amount of calories and do the exercise and activity you said you are doing on the calculator.

Step four: Watch the weight come off although you might go up the first week or two but don't give up.

Step five: Recalculate every 5 to 10 lbs.

I don't think I can make it any more simple than that! (Can you tell I used to teach primary kids? ;-) )