When online calculators give you a figure for calories burned doing an activity, does that figure include calories that you would have burned as part of your BMR whether or not you'd done that activity?

For example, I want to know how many calories I have burned today at work as a sales person, on my feet for 8 hours. The figure given is pretty high, around 600-800 cals. So, is this 600 cals MORE than I'd have burned just being alive, or does being alive plus working on your feet equal 600 all together?