Calories Lost (2 technical questions about BMR)

Pentdad

Hey folks fatman here again.

Okay so my question is this:

1. When you see someone say 'you will use 200 calories if you run a 6mp for 30 mins' do they mean you will use 200 just because of the exersise, or does that also include the BMR standard rate?

So for example our organs use up something like 80 calories an hour to keep functioning- I just wondered if this was included, meaning for example you would lose 120 from the running and 80 that you would have lost anyway if you had stood still.

2. I know BMR is not exact science, but I have been quoted 2100 by MFP all the way up to 3000 on other sites. Is there any reason why this is so wildly different when they supposedly use the same equation?