The first step in determining the BTUs needed to cook your steak is knowing the thickness of the steak. Let's say the steak is 1 inch thick. Next, you want to know if you will be cooking it with the bone in or not. If you are, then you will add 5 percent more BTUs. So if the steak is 1 inch thick with the bone in, you'll need 18,000 BTUs. If the steak is 1 inch thick without the bone in, you'll need 16,000 BTUs. If the steak is 2 inches thick with the bone in, you'll need 36,000 BTUs. If the steak is 2 inches thick without the bone in, you'll need 32,000 BTUs.