Understanding Roofing Calculations
Calculating roofing materials involves more than just length × width. You must account for the roof's slope (pitch) and a waste factor for cuts and overlaps.
What is a "Square"?
In roofing, materials are measured in squares. One square equals 100 square feet of roof area. Most shingle bundles are sold such that 3 bundles cover 1 square.
Roof Pitch Multipliers
As a roof gets steeper, its surface area increases relative to the footprint of the house. This calculator assumes a standard 4:12 pitch (moderate slope) by default, but you can adjust it. Steep roofs (above 8:12) require significantly more material.
Frequently Asked Questions
How many bundles of shingles do I need for a 2000 sq ft roof?
A 2000 sq ft roof is 20 squares. Typically, you need 3 bundles per square, so you would need 60 bundles. Always add 10-15% for waste.
What is roof pitch?
Pitch is the steepness of the roof, calculated by the rise in inches for every 12 inches of horizontal run. A 4/12 pitch means the roof rises 4 inches for every foot.
How do I calculate squares for roofing?
Divide the total roof area (in square feet) by 100. For example, 2500 sq ft = 25 squares.
