Hi,
The formula for the lightning protection, Franklim pole type:
Rp=h*tan A
Where Rp is the radius of protection of a cone defined by the formula, with the height h in meters (h is the top point of the pole) and A is the angle in degrees at the top, that usually is 55º for a class IV degree of protection.
For an electronic protection pole, the formula is rader complicated, and for that you should contact the manufacters because they have tables for each equipment.
Best Regards,
Adriano