HazardsMind:
I don't think there is an actual way, because all motors/servos are not the same. Unless you code it yourself with set ranges (between 5 - 12 inches, turn this much) that's what I did for my robot.
Did you do a similar project?... But how will it know how much to turn, for example if its 5 inches or 50 inches?
And, I did not figure out how to use both sensors at once, going back to my first question, it didnt work, it only shows me one sensor!