Roast your whole chicken at 400 degrees for 30 minutes, which browns the chicken quickly and cuts down the cooking time as well. From there, reduce the heat to 350 degrees and roast another 45-60 minutes or until a thermometer inserted into the thickest part of the thigh without touching the bone registers at 175 degrees. You can certainly roast your chicken at 350 degrees the entire time, which will take a while longer.