When Wes of MSTN gives the "height on center" of the LaRue mounts, that means the height of the center of the optic measured from the flat-top, correct?

A ballistics program uses the HOB (height over bore) measurement to make guess-timations on drop at distance, where HOB is from the center of the optic to the center of the bore.

In trying to do the math, I'm stuck somewhere between 1" and 1.2", but I need to know for certain as that .2" makes a big difference in my 300+ yard figures.

Can anyone tell me for sure how tall the flat top is above the bore of an AR15?

Thanks!