How to handle valleys and hips?

Add 10% extra material for valleys and hips. These areas require additional shingles for proper coverage and weather protection.

What about ventilation requirements?

Plan for proper ridge and soffit vents. The general rule is 1 square foot of ventilation per 300 square feet of attic space, split between intake and exhaust.

Roofing Calculator

Q: What is a roofing square?

A roofing square equals 100 square feet of roof area. It's the standard unit used in the roofing industry for material calculations and pricing.

Q: How to calculate waste factor?

Add 10-15% to your total material calculation for waste. Complex roofs with valleys, hips, and dormers may require 15-20% waste factor.

Q: What affects material quantity?

Roof complexity, pitch, valleys, hips, dormers, and waste factor all affect material quantity. Steeper roofs require more material due to increased surface area.

Roof Parameters

Roof Type

Select roof style

Length

Roof length

Width

Roof width

Roof Pitch

Roof slope

Material Type

Select roofing material

Calculation Results

Roofing Calculator: Your Guide to Roof Materials

Need to calculate your roofing materials? Our Roofing Calculator helps you determine the exact amount of materials needed for your roofing project, including shingles, underlayment, and other components.

Understanding Roofing Calculations

Roofing calculations are important for several reasons:

Material Planning: Accurate material estimates
Cost Control: Budget management
Waste Reduction: Minimize excess materials
Project Efficiency: Proper planning
Quality Assurance: Complete coverage

How to Use the Roofing Calculator

Select Roof Type: Choose the roof style
Enter Length: Input roof length
Enter Width: Input roof width
Enter Pitch: Input roof slope
Select Material: Choose roofing material
Click Calculate: Get material estimates

Roofing Calculation Formulas

Roof Area:
A = L × W × Pitch Factor

Material Quantity:
M = (A × 1.1) ÷ Coverage

Underlayment:
U = (A × 1.1) ÷ 400

Where:
A = Roof area (sq ft)
L = Length
W = Width
M = Material quantity
U = Underlayment rolls

Common Roofing Materials

Asphalt Shingles:
- Coverage: 100 sq ft per bundle
- Weight: 60-80 lbs per bundle
- Warranty: 20-30 years
- Use: Residential
Metal Roofing:
- Coverage: 100 sq ft per square
- Weight: 40-60 lbs per square
- Warranty: 40-70 years
- Use: Residential/Commercial
Tile Roofing:
- Coverage: 100 sq ft per square
- Weight: 600-1000 lbs per square
- Warranty: 50-100 years
- Use: Premium residential
Slate Roofing:
- Coverage: 100 sq ft per square
- Weight: 800-1200 lbs per square
- Warranty: 75-200 years
- Use: Luxury homes

Real-World Examples

Example 1: Standard Asphalt Shingle Roof

Roof Type: Gable
Length: 40 feet
Width: 30 feet
Pitch: 30 degrees
Material: Asphalt Shingles
Results:
- Roof Area: 1,386 sq ft
- Shingle Bundles: 16
- Underlayment Rolls: 4
- Ridge Cap: 30 linear feet
- Drip Edge: 140 linear feet

Example 2: Premium Metal Roof

Roof Type: Hip
Length: 50 feet
Width: 40 feet
Pitch: 35 degrees
Material: Metal Roofing
Results:
- Roof Area: 2,440 sq ft
- Metal Panels: 25 squares
- Underlayment Rolls: 7
- Ridge Cap: 40 linear feet
- Drip Edge: 180 linear feet

Frequently Asked Questions

What is a roofing square?

100 square feet of roof area.

How to calculate waste factor?

Add 10-15% for standard roofs.

What affects material quantity?

Roof complexity, pitch, and waste factor.

How to handle valleys?

Add 10% extra material for valleys.

What about ventilation?

Plan for proper ridge and soffit vents.