How long does it take to cook a half inch steak medium?

A steak 1/2-inch thick will usually cook in 2 to 3 minutes per side for medium-rare, or 3 to 4 minutes per side for medium. Remember that using an instant-read thermometer is the most accurate way to determine doneness - for medium, the steak should be removed from heat at an internal temperature of 130 - 140°.