Roof footprint (ground floor area)
Measure the outside footprint of the house at ground level including any garage or attached structures under the roofline.
Roof pitch
Medium pitch (4/12 to 6/12) is the most common for residential homes. The steeper the roof, the more material you need.
Roof shape
A gable roof has two slopes meeting at a ridge. The simplest shape with the least waste.
Frequently Asked Questions About Roof Shingles
How many shingles do I need for my roof?
Shingles are measured in ‘squares,’ where one square equals 100 square feet of roof area. To find how many you need, calculate your roof’s total square footage (including pitch), divide by 100 to get squares, and add about 10% for waste. Most asphalt shingles come three bundles to a square. For example, a 2,000 square foot roof is 20 squares, or about 60 bundles plus waste. Our Roof Shingle Calculator factors in pitch and waste automatically.
How do I account for roof pitch when measuring?
A steeper roof has more surface area than its ‘footprint,’ so you multiply the flat (ground) area by a pitch multiplier. For example, a common 6/12 pitch uses a multiplier of about 1.12, an 8/12 pitch about 1.20, and a 12/12 pitch about 1.41. Measure your home’s footprint, then apply the multiplier for your roof’s slope to get the true roof area before dividing into squares. Skipping this step leaves you short on shingles for any sloped roof.
What else do I need besides shingles?
A complete roof needs underlayment (felt or synthetic) covering the whole deck, ice-and-water shield along eaves and valleys in cold climates, starter strip shingles along the edges, ridge cap shingles for the peaks and hips, roofing nails, drip edge metal, and flashing around chimneys, vents, and walls. Plan underlayment by the roll (each covers a set number of squares) and nails at roughly 320 per square. The calculator focuses on shingle quantity; budget these accessories separately.
What type of roofing shingle should I choose?
Three-tab asphalt shingles are flat, uniform, and economical, offering decent life for the price. Architectural (dimensional) asphalt shingles are thicker, layered for a textured look, more wind-resistant, and longer-lasting, making them the most popular residential choice. Premium options include designer asphalt, wood shakes, metal, slate, and tile, each with different lifespans, weights, and costs. Heavier materials like slate and tile may require extra structural support. Match the shingle to your climate, roof structure, and how long you want it to last.
How many bundles of shingles are in a square?
Most architectural and three-tab asphalt shingles come 3 bundles per square (100 square feet), though some heavier or premium shingles come 4 or even 5 bundles per square. Always check the specific product, since bundle coverage varies. A bundle typically weighs 50 to 80 pounds, so factor that into delivery and getting them onto the roof. Calculate your squares first, then multiply by the bundles-per-square for your chosen shingle to get the bundle count.