The length of time needed to broil a porterhouse steak depends somewhat upon individual taste. As a general rule, broiling the steak for 4 minutes per side --a total of 8 minutes-- produces meat that is medium rare.
Cooking time varies for steak, because people have preferences for the "degree of doneness." Rare beef is cooked to 140 degrees Fahrenheit and is pink on the inside. The inside of medium rare beef is brown around the edges but still mostly pink. Its temperature is 145 degrees. A medium-cooked steak is pinkish-brown on the inside, and the temperature is 160 degrees. Well-done steak is cooked to 170 degrees, and the inside is primarily brown.