Roofing material estimator
Enter your roof size, pitch, and how many similar sections you are covering. Results include area, squares, shingle bundles with waste, underlayment rolls, and ridge cap length.
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Frequently asked questions
- What is a roofing square?
- A roofing square is 100 square feet of roof surface. Suppliers price shingles and many accessories by the square, so converting your roof area into squares is the first step toward an accurate order.
- How much waste should I add for shingles?
- Most residential jobs add about 10% extra field shingles for cuts, starter courses, and small mistakes. Complex roofs with many valleys or dormers may need more; simple gable roofs often stay close to 10%.
- Do I measure the roof on the slope or from the ground?
- Measure the horizontal footprint from the ground or a plan—length and width as if looking straight down. The calculator applies pitch with a slope factor so you do not need to walk the roof to get surface area.
- How many bundles are in a square of shingles?
- Architectural shingles commonly use three bundles per square before waste. Always check the label on the product you buy, since bundle coverage can vary by brand and shingle type.
- Does this calculator include hips and valleys?
- The estimate assumes a straightforward rectangular section. Hips, valleys, skylights, and steep transitions need extra material; use the result as a planning baseline and confirm tricky areas on site.
How to use this roofing calculator
Start with the horizontal size of the roof as if you were looking straight down from above. Roof length and roof width are the two main edges of that footprint, in feet or feet plus inches. You are measuring the outline the roof covers, not walking the slope.
Pitch is steepness as rise over a twelve-inch run. Steeper pitches spread shingles across more square feet. When you click Calculate, you get roof area, squares, bundles with ten percent waste, underlayment rolls, and ridge cap length.
Related guide
Measure your roof footprint, account for pitch, and order shingles with confidence—no contractor spreadsheet required.
Read: How to Estimate Roofing Materials: A Homeowner's Guide →