Roofing calculator

How it works

Sloped roof area is the plan area including overhangs divided by the cosine of the pitch angle. In imperial, shingles are sold in squares (100 ft²), usually three bundles per square.

How to measure

Measure the building footprint and the eave overhang. Enter pitch in degrees; see the hint for common x/12 pitches.

Tips

• Ridge caps and starter strips are counted separately.
• Roof work carries a fall risk; use proper fall protection.
• Raise waste to 15% on complex roofs with hips, valleys and dormers.