Ask five grill owners how they time their steaks, and you'll get five different answers. Simplify cooking by following the 10 percent rule, which says the thickness of a medium-cooked steak equals 10 percent of the cooking time. Measure the steak's thickness in inches, then multiply that number by 10. Adjust the cooking time if you prefer your steak more or less rare.
The 10 percent rule applies to room-temperature meat, so remove the steak from the refrigerator about an hour before you light the grill. This gives the steak time to warm up, and also helps it dry. A dry surface sears faster than a moist one, and allows the meat to brown before the steak has finished cooking.
Grilling the Steak
Time the cooking carefully. Cook the steak over the hottest part of the grill for about 60 percent of the cooking time, until the bottom of the steak sears and beads of liquid rise to the surface. Flip the steak using tongs, and leave it for the remaining minutes. Move the steak to a cooler part of the grill if it sears too quickly.
A minute or two before the cooking time is up, use a steak thermometer to test the meat. Adjust the remaining cooking time based on the internal temperature. Although the U.S. Department of Agriculture recommends cooking meat to at least 145 degrees Fahrenheit, many cooks remove it from the heat at 140 F for medium doneness.