How many roofing shingles required for a 12x20 single car garage?

To calculate the number of roofing shingles needed for a 12x20 single car garage, first determine the total roof area. Assuming a simple gable roof design with a 4:12 pitch, the roof area would be approximately 480 square feet. Typically, a bundle of shingles covers about 33 square feet. Therefore, you would need roughly 15 bundles of shingles, accounting for waste and overlap. Always consult with a roofing professional for precise estimates based on specific roofing styles and local building codes.