The installed cost of a metal roof is subject to the same variables that determine any roofing installation: roof size, roof pitch (steep roofs cost more), and roof complexity (the number of valleys, ridges, skylights, and dormers). That said, you can expect a metal roof to cost two or three times as much as an asphalt shingle roof. A metal roof typically costs about the same as a tile or cedar shingle roof, but less than a slate roof.