ball and cup pushrods

I am going to try and get my proper push rod length this weekend and have never used adjustable rockers. So my adjustable rockers came by ups and have complete instructions, but in the instructions it doesn't point out where to measure the push rod tool. They are ball and cup style rockers.
Do I measure from the bottom of the ball to the top of the tool or do I have to find some way to get the measurement from ball to the inside of the cup where the rocker ball sits? I'm not completely sure. They advertise good tech support, but I just thought I'd ask here first to see if anyone knew.
Thanks in advance.