I don't understand BMR

What is your height and weight? How many pounds a week do you have MFP set for you to lose? What type of workout do you do? Can you open up your food diary so we can see what you are eating in a day?

I found this site which does a very good job of explaining two different ways of calculating your BMR, what it is, and how to use that information when figuring out your goal calorie intake. http://www.shapefit.com/basal-metabolic-rate.html

BMR is confusing, or should I say all the different interpretations and definitions are confusing.

BMR is that number of calories that you need to maintain your current weight at your current activity level.

You can do two things to reduce your weight.

Increase your activity level while maintaining the same amount of calories (bmr) or:

Reduce your calorie intake without increasing your activity level.

Either should result in a reduction of weight.

If you continue to consume the calories indicated in your BMR, and change nothing else, your weight will not change. I don't understand folks that say you "Must eat at least your BMR to lose weight". Again, your BMR is what you need to MAINTAIN your current weight.

BMR is your resting calorie burn. Basically, it is the caloric burn if you have no other activity (staying in bed all day is the popular analogy). Activities burn more calories on top of that weight.

Eating extremely low calories is a risky diet strategy (I won't go into it, because there are constantly threads going into detail on it), particularly for those without a ton of weight to lose or that have naturally low BMR's (older, shorter, relatively small builds). Therefore, the common wisdom is that people (anonymously on the internet with no medical training, details of your situation, or any stake in your health) shouldn't recommend eating below their BMR (again, calories burned sans any activity) for fear of treading onto dangerous ground. This is a policy that I heartily support. It may be something you can do, but you should get sound medical advice from your personal doctor who knows you and your situation before doing so.

In the meantime, the common wisdom around here is to eat at least your BMR and then use activity calories (exercise, walking, etc) to build the deficit from which you will lose weight.

Most of the BMR I have seen (used) inlcude my activity level in its computations. So if it gives me a bmr of 2000, including activity, then how can I lose weight if I consume 2000 and don't change my activity level. If nothing else changes (activity) then you must reduce calories below the BMR to lose weight. I am not saying reduce it by half, but a few hundred calories to attain a small weight loss per week.

If it's including activity, it's not a BMR calculator. BMR is resting calorie burn, before any activity. This is what your body burns just keeping you alive (heartbeat, breathing, organ functions, etc.)

When you include daily activity, it becomes your TDEE (Total Daily Energy Expenditure). This number is the total of what you burn on a given day, including activity, exercise, etc. This is the number to create your deficit from.

Exercising and eating 1200 calories is not working. It's been a month and theres absolutely no change at all. So which website am I supposed to believe?

Shocking. Eat more.