Lightning Rod Calculator
Lightning Rod
Calculate lightning protection requirements for a building.
Formula
Rods = 2 x (ceil(L/Spacing) + ceil(W/Spacing) + 2) - 4
Frequently Asked Questions
How does a lightning rod work?
It provides a low-resistance path to safely direct lightning current into the ground.
How far apart should lightning rods be?
NFPA 780 requires air terminals spaced no more than 20 to 25 feet apart.