Roofing Calculator 🏠

How to Use the Roofing Calculator

Select your roofing material type (shingles, metal, tiles, or underlayment), choose your measurement system, and enter your roof dimensions. Enter the roof pitch either as a rise/run ratio (e.g., 6/12) or as an angle in degrees. For bundled products like shingles or tiles, enter the coverage per bundle from the product label. For sheets or rolls, enter the dimensions. The calculator automatically accounts for roof pitch and adds your chosen waste allowance percentage to calculate the total materials needed.

Understanding Roof Pitch

• Pitch is the slope of your roof, commonly expressed as rise over run (e.g., 6/12 means 6 inches of rise for every 12 inches of horizontal run).
• A steeper pitch requires more material to cover the same horizontal area. The calculator automatically adjusts for this.
• You can enter pitch as a ratio (rise/run) or as an angle in degrees. Common residential pitches range from 4/12 (18.4°) to 12/12 (45°).
• For flat or very low-slope roofs, use a small pitch value or 0° to minimize adjustment.

Material Planning Tips

• Always order 10-15% extra material for waste, cuts, and future repairs—the calculator includes this automatically.
• For complex roofs with valleys, dormers, or hips, use a higher waste factor (15-20%) to account for additional cuts.
• Verify all measurements carefully. Measure the horizontal projection of the roof, not the sloped surface.
• Check that all bundles or sheets are from the same manufacturing batch for consistent color and quality.
• Consider climate and local building codes when selecting materials and overlap requirements.

Typical Coverage Reference