Calculator
Roof Pitch Calculator & Material Estimator
Enter your building footprint and pitch (rise/run or degrees). We’ll estimate roof surface area and how many bundles, panels, or tiles to order — including waste.
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<iframe src="https://boringtools.app/en/embed/roof-pitch" title="Roof Pitch Calculator & Material Estimator" loading="lazy" style="width:100%;min-height:720px;border:1px solid #D6D0C6;border-radius:2px;" ></iframe> <p style="font:14px/1.4 system-ui,sans-serif;margin:8px 0 0;"> <a href="https://boringtools.app/en/tools/roof-pitch">Roof Pitch Calculator & Material Estimator</a> — Calculator by Boring Tools </p>
What we calculate
Three linked steps — the same sequence you see when you hit Calculate.
Pitch
Rise over run (or angle) becomes a pitch factor — how much steeper the roof is than the floor plan.
Area
Footprint × pitch factor (plus overhangs) estimates the true roof surface. Use waste % for hips and valleys.
Materials
Surface area is divided by coverage per bundle, panel, or tile, then padded with your waste factor.
Frequently asked questions
What is roof pitch?
Roof pitch describes how steep a roof is. In the U.S. it is usually written as rise over run — for example 6/12 means the roof rises 6 inches for every 12 inches of horizontal run. You can also express pitch as an angle in degrees.
How do you convert pitch to roof area?
Start with the building footprint (length × width), optionally add overhangs, then multiply by the pitch factor √(1 + (rise/run)²). Steeper roofs have a higher factor, so they need more covering than a flat plan view suggests.
What is a roofing square?
One roofing square equals 100 square feet of roof surface. Suppliers often price and pack materials by the square. Our estimator also converts that into bundles, panels, or tiles depending on the material you choose.
Why include a waste factor?
Cuts, hips, valleys, starter courses, and mistakes mean you order more than the raw area. Ten to fifteen percent is a common starting point for simple gable roofs; complex roofs may need more. Adjust the waste field to match your project.
How many bundles of asphalt shingles do I need?
Most three-tab or architectural shingles cover about 33.3 square feet per bundle (three bundles per square). We divide your roof area plus waste by that coverage and round up so you have a practical order quantity.
Is this accurate enough to order materials?
It is a solid planning estimate for rectangular footprints and typical pitches. Irregular plans, dormers, multiple hips, and local product coverage can change counts. Always confirm with a contractor or supplier before placing a large order.