It depends on many factors… that is why the calibration routine asks you to enter it roughly, and then it is determined by the movement of the machine.
M360, M361 and M364 are codes designed to bring you close to where you need to be, and then adjust by hand until the condition is met (Arm parallel to platform in one, 90deg between arms in the other.
if M360 does not work, jig it by hand until it is in the right position, M114, and do the M206 step.
Then jog by hand until the arm is 90deg to platform, and take the reading as per the flowchart. This is the way to get the real M92 step values.