Roofing Calculator
Calculate roof area and estimate roofing costs for gable and shed roofs
Calculate Roof Area & Cost
House Dimensions
Length of the house measured on the ground
Width of the house measured on the ground
Roof Pitch
Cost Estimation (Optional)
Include materials and labor costs
Roofing Calculation Results
Please Complete Required Fields
- ⚠️Please enter a valid house length
- ⚠️Please enter a valid house width
- ⚠️Please enter a valid roof pitch
Roof Classification
Area Calculation
Formula used:
Roof Area: Base Area ÷ cos(Pitch Angle in degrees)
Total Cost: Roof Area × Unit Price
Example Calculation
100m² House with 25° Roof Pitch
House Dimensions: 10m × 10m = 100m²
Roof Pitch: 25° (46.6% slope, 5.5:12 ratio)
Unit Price: $50 per m²
Calculation Steps
1. Base Area = 10m × 10m = 100m²
2. Roof Area = 100m² ÷ cos(25°) = 100 ÷ 0.906 = 110.34m²
3. Total Cost = 110.34m² × $50/m² = $5,517
Result: 110.34m² roof area costing $5,517
Roof Type Guide
Low Pitch
Less than 10°
Minimal snow/rain areas
Standard
10° to 25°
Most common residential
Steep
25° to 45°
Good for heavy snow
Very Steep
Over 45°
Specialized construction
Cost Estimation Tips
Get quotes from multiple contractors
Consider material quality differences
Factor in waste and additional materials
Include removal of old roofing if needed
Add 10-15% buffer for unexpected costs
Note: Prices vary significantly by location and market conditions.
Understanding Roofing Calculations
How Roof Area is Calculated
The roof area is calculated by dividing the house base area by the cosine of the roof pitch angle. This accounts for the additional surface area created by the sloped roof.
Why Roof Pitch Matters
- •Water Drainage: Steeper roofs shed water more effectively
- •Snow Load: Higher pitch helps snow slide off
- •Material Requirements: Affects choice of roofing materials
- •Surface Area: Higher pitch means more roofing material needed
Roof Types Supported
Gable Roof
Two sloping sides that meet at a ridge. Most common residential style.
Shed Roof
Single flat surface that slopes to one side. Simple construction.
Formula: Roof Area = Base Area ÷ cos(Pitch Angle)
Cost Estimation Guidelines
Basic Materials
Asphalt shingles, basic underlayment. Typically $2-3 per sq ft including labor.
Standard Materials
Architectural shingles, quality underlayment. Typically $3-4 per sq ft including labor.
Premium Materials
Metal, tile, or slate roofing. Can range from $4-15+ per sq ft including labor.