I regret to say that I've forgotten most of the calculus that I knew, I don't use it at all in my line of work. However, I do use a lot of trigonometry and geometry though, so maybe that makes it up for it. I shouldn't have to use trig and geometry, but you might be amazed how many times the engineers' drawings come out "off". I know guys that do flame bending, and use a lot of advanced calculations for that, but I've never messed with that personally.
