Roofing Calculator
Calculate roof area, materials, pitch, and cost for gable, hip, and flat roofs. 4 calculation modes with step-by-step solutions.
Calculate
Select a calculation type, enter your measurements, and click Calculate to see roof area, materials, pitch, or cost with step-by-step solutions.
Result
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Step-by-Step Solution
Complete User Guide
What is the Roofing Calculator?
The Roofing Calculator helps you plan any roofing project by calculating the roof area (adjusted for pitch), the number of material bundles and roofing squares needed, roof pitch from rise and run measurements, and the total project cost including materials and labor.
4 Calculation Modes
Roof Area
L × W × pitch multiplier. Gable, hip, flat.
Materials
Bundles & squares for 6 material types.
Pitch
Rise/run → X:12, angle°, slope%.
Cost
Squares × price + labor = total.
Common Roof Pitches
| Pitch | Angle | Multiplier | Type |
|---|---|---|---|
| 2:12 | 9.5° | 1.014 | Low slope |
| 4:12 | 18.4° | 1.054 | Standard |
| 6:12 | 26.6° | 1.118 | Moderate |
| 8:12 | 33.7° | 1.202 | Steep |
| 12:12 | 45.0° | 1.414 | Very steep |
Material Coverage
🏠 Asphalt shingles: 33.33 ft² per bundle (3 bundles/square)
🪵 Wood shingles: 25 ft² per bundle (4 bundles/square)
🪨 Slate, clay, metal, rubber: 100 ft² per square
Important Notes
- 1 roofing square = 100 ft². All material estimates use this unit.
- Include overhangs and eaves in your measurements.
- Use 10% waste for simple roofs, 15–20% for valleys and dormers.
- Always get professional quotes for large projects.