I guess every one has to learn some time or other, but you are kidding aren't you?
45° tapers are the easiest ones to calculate out.
The distance you move on Z is the same for X (on radius).
so... if your diameter is 0.500" and your size of chamfer is 0.025" and you are starting 0.100" away from the face your X point would be 0.100" in front of your Z face and your X value would be calculated from 0.500-(2x0.025)-(2x0.100) = 0.250"
Do you know how to use Trigonometry at all? as in Sin Cos and Tan?
Hope you can follow this... once you understand how to calculate the points, machining chamfers other than 45° becomes rather straight forward.