new, lost and confused

Totally different or within a few numbers different? I used a few of them to get an average, but my numbers were close. It is a math formula and I believe the variation is based on how much rounding the site uses in its formula.

MFP has calculators, but I am sure people will have others to recommend, too. There is also this feed... http://www.myfitnesspal.com/topics/show/931670-bmr-and-tdee-explained-for-those-needing-a-guide

http://www.myfitnesspal.com/tools/bmr-calculator

Your BMR is your Basal Metabolic Rate. This is how much energy it takes you to simply be alive each day. Breathe, digest, think, etc.

Your TDEE is your Total Daily Energy Expenditure. This is based on your BMR plus the energy you generally expend at work, around the house, chasing the kids, exercising, etc. Most people try to eat somewhere in the middle of the two - your TDEE less your BMR. I have seen calculations that say to use your BMR plus 20%, but everyone is different. You have to find what works for you. Any deficit should cause some weight loss. The pacing is really preferential.

Here is the TDEE I used... http://iifym.com/tdee-calculator/

Oh, and if you are in for significant losses, recheck your numbers periodically and adjust your intake/deficit.

Hope this helps.