I mean ya, there are option calculators, have I ever used one?? Nope, so I cant tell you much about them, you can search them out online and see how they work, but as Ralph said, pay attention to your greeks over anything else. Again, I know the reason why you want to do this, but in time, you will get good enough and you will have the "feel" of how stock options move with the stock and you will be able to mark your profits and stops the way you need to just by going over things in your head, give it time