How Long Do You Grill Hamburgers? The answer depends largely on the thickness of your patties. The best thickness for cooking is about 1/2 to 3/4 thick. Cook the patties for 10 to 16 minutes, until the hamburger patties reach an internal temperature of 155 degrees for 15 seconds at the thickest part of the patty. Don't rely on the color of the meat to judge doneness.