not perfect, but I'd like to use it at least as a general guide.

This site has one as a "calculator" where you plug in some info and it gives you a number:



Others I've seen actually write it out as a formula.

But I don't think I really understand what the number means? Is this the number of calories I'll burn just by sitting around all day? Or is it an average? Or does it take normal activity into account?

Like I said, I know it's not gonna be perfect, but I like the idea of it just as a general guide. I just need to understand what it's actually telling me.