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Professional Roofing Calculator
Guide
Basic Measurements
Roof Length (feet)
ⓘ
Please enter a valid length.
Roof Width (feet)
ⓘ
Please enter a valid width.
Roof Pitch
ⓘ
1/12 (4.8° - Almost Flat)
2/12 (9.5° - Slight Slope)
3/12 (14.0° - Low Slope)
4/12 (18.4° - Standard)
5/12 (22.6° - Medium)
6/12 (26.6° - Steep)
7/12 (30.3° - Steeper)
8/12 (33.7° - Very Steep)
9/12 (36.9° - Extra Steep)
10/12 (39.8° - Extremely Steep)
11/12 (42.5° - Ultra Steep)
12/12 (45.0° - Maximum Steep)
Additional Features
Number of Valleys
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Number of Chimneys/Skylights
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Waste Factor
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10% (Simple Roof)
12% (Standard)
15% (Complex Roof)
17% (Very Complex)
Calculate Materials
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Calculation Results
Total Roof Area
0 sq ft
Roofing Materials
0 squares
0 bundles
Additional Materials
0 rolls
0 lbs
Flashing Needed
0 linear ft
0 pieces
Additional Recommendations
Roofing Calculator Guide
How to Measure Your Roof
Measure the length and width of each roof section from the ground
For the pitch, use a pitch gauge or estimate based on roof type
Count the number of valleys (where roof sections meet)
Count chimneys, skylights, and other major penetrations
Understanding Waste Factor
10%: Simple gable roof with few or no penetrations
12%: Standard roof with some penetrations
15%: Complex roof with multiple valleys and penetrations
17%: Very complex roof design with numerous cuts required
Material Guidelines
1 Square = 100 square feet of roof area
Typical 3-tab shingles come in bundles of 3 per square
Architectural shingles usually come in bundles of 4 per square
Underlayment rolls typically cover 4 squares (400 sq ft)
Plan for 1.5-2 lbs of nails per square