How do you calculate your calories?

Maiducali

I have heard many different ways of eating your calories and burning them.

Some say;
Eat 1200 and you won't have to worry about burn calories, of course this isn't me, I need more than that and I want to workout

others say;
calculate what your body needs, add 500 calories (the amount you aim to burn on a daily or most day basis) and then minus 250,500, 750, or 1000 calories depending how many pounds you wanna burn

then I heard;
eat the calories needs for your goal weight.

What does everyone else do?