The first step in estimating the cost of roof shingle replacement is to consider the type of shingles being installed. There are various materials available, including asphalt, wood, metal, and slate, each with its own price range. Asphalt shingles are the most common choice among homeowners due to their affordability and durability, typically costing between $90 to $100 per square (a square equals 100 square feet). Wood shingles, while aesthetically pleasing, can range from $150 to $200 per square, and more premium options like slate can be significantly more expensive, often exceeding $300 per square.