Accuracy of the burn meter- how to find your burn amount?

I read that generic calculations of what you burn could be off by 100’s of calories. One way to find you ‘real’ burn is by monitoring your burn/calorie intake against your lose loss/gain. For example: I am trying to stick to 1400-1600 cal a day and have been losing successfully for 3 weeks. Then last week, TTOM came and I was cranky so I ate 1800-2000 cal a day. I didn’t gain/lose anything. So now I think that my burn might be about 2000 versus the 2200 my burn meter says.

My questions are:

Has anyone heard of other methods to find your actual daily burn?

Also, I am sure there was some water weight responsible for no gain/loss last week, but could there be any other reasons? A friend mentioned this is normal when starting out (e.g. beginner weight loss, then a week plateau). Is this right?

Try is http://www.bmi-calculator.net/bmr-calculator/
or Discovery Health website http://health.discovery.com/tools/calculators /basal/basal.html

I found there are only a few calories discrepency between them all.

Thanks April-

Yeah, it's what i thought... they both read around 1850 (if i slept all day).

We have the same BMR when we are sedentary!!!

Yes, I recommended a long time ago that the analysis have the net calories tracked against actual weight loss, so the burn estimate could be adjusted... but like so many suggestions, it disappeared into the ether.