Shed Roof Calculator
Calculate dimensions, materials, and costs for your shed roof project.
Enter rise in inches per 12 inches of run
Shed Roof Calculation Results
Roof Dimensions:
- Roof Area: sq ft
- Actual Rafter Length: ft
- Roof Rise: ft
- Roof Angle: degrees
Materials Needed:
- Roofing Material:
- Underlayment: sq ft
- Drip Edge: ft
- Ridge Cap: ft
* Estimates include waste factor. Consult with a professional for precise material requirements.
Disclaimer: This calculator provides estimates for planning purposes only. Actual material requirements may vary. For structural integrity and safety, please consult with a qualified contractor or engineer before beginning construction. Always follow local building codes and safety guidelines.
About Our Shed Roof Calculator
Our Shed Roof Calculator is designed to help DIY enthusiasts, homeowners, and contractors accurately plan and estimate materials for shed roof construction. Whether you're building a new shed or replacing an existing roof, this calculator provides the measurements and material quantities you need for a successful project.
Understanding Shed Roof Design
A shed roof (also known as a skillion roof or lean-to roof) is characterized by its single sloping surface. The simplicity of this design makes it popular for garden sheds, additions, and modern architectural styles. Key elements to consider include:
- Roof Pitch: The steepness of the roof, typically expressed as a ratio (e.g., 4:12 means 4 inches of rise for every 12 inches of horizontal run)
- Overhang: The distance the roof extends beyond the walls, providing protection against water runoff
- Materials: Different roofing materials offer varying durability, cost, and aesthetic appeal
How Our Calculator Works
Our calculator determines key measurements and material requirements based on your input:
- Roof Area: Calculated from width, length, pitch, and overhang
- Rafter Length: Determined using the Pythagorean theorem based on roof width and pitch
- Material Quantities: Estimated based on the total roof area plus your specified waste factor
- Roof Angle: Converted from pitch ratio to degrees for reference
Key Features:
- Calculate precise roof dimensions based on your measurements
- Estimate material quantities with customizable waste factors
- Support for multiple roofing material types
- Instant results for rafters, underlayment, drip edge, and ridge cap
- User-friendly interface for quick project planning
How to Use:
- Enter the width and length of your roof in feet
- Specify the roof pitch (rise in inches per 12 inches of run)
- Enter the overhang distance in inches
- Select your preferred roofing material
- Adjust the waste factor percentage if needed
- Click "Calculate Roof Requirements" to see the results
Roofing Material Options:
Asphalt Shingles: Affordable, available in various styles and colors, typically sold in bundles covering 33.3 sq ft.
Metal Roofing: Durable, fire-resistant, and energy-efficient, typically sold in sheets or panels.
Cedar Shakes: Natural appearance with good insulation properties, though requiring more maintenance.
Rubber Roofing (EPDM): Excellent for low-pitch roofs, highly durable, and resistant to UV damage.
Corrugated Metal: Economical and quick to install, suitable for utility sheds and agricultural buildings.
Important Considerations for Shed Roof Construction
- Local Building Codes: Always check local regulations regarding shed construction and permitting requirements
- Weather Conditions: Consider your local climate when selecting roof pitch and materials
- Structural Support: Ensure your shed walls and framing can support the roof design
- Ventilation: Proper ventilation can extend roof life and prevent moisture problems
- Professional Consultation: For larger sheds or complex designs, consult with a professional builder or engineer
Whether you're a DIY enthusiast planning your first shed or an experienced builder creating detailed estimates, our Shed Roof Calculator provides the accurate information you need for a successful project.
Frequently Asked Questions
What's the ideal pitch for a shed roof?
The ideal pitch depends on your location and intended use. For areas with heavy snow, a minimum pitch of 4:12 is recommended to allow snow to slide off. In areas with minimal precipitation, pitches as low as 1:12 may be sufficient with appropriate materials. For optimal drainage while maintaining a low profile, a 3:12 pitch is a common compromise. Steeper pitches (6:12 and above) provide better resistance to leaks and more interior headroom but require more materials.
How do I determine the right overhang length?
Overhangs typically range from 6 to 12 inches for most shed applications. Consider these factors: larger overhangs (9-12 inches) provide better wall protection from rain but may require additional bracing in areas with high winds; smaller overhangs (4-6 inches) are simpler to construct and may be sufficient in milder climates. For sheds with doors or windows along walls, slightly longer overhangs above these openings can provide additional protection.
What roofing material is best for a low-pitch shed roof?
For low-pitch shed roofs (below 3:12), seamless materials that resist water infiltration are best. Rubber roofing (EPDM) is excellent for pitches as low as 1:12, offering durability and water resistance. Standing seam metal roofing works well for pitches of 2:12 and above. Modified bitumen or roll roofing can be used for pitches of 2:12 to 3:12. Traditional asphalt shingles aren't recommended for pitches below 3:12 as they're more prone to water infiltration at these lower angles.