Roofing Calculator

Calculate roofing materials, costs, and measurements for your roofing project. Get accurate estimates for shingles, underlayment, and other roofing materials.

Roof Measurements

Material Selection

Material Requirements

1342 sq ft
Total Roof Area
(1476 sq ft with 10% waste)

Shingles

45
Bundles Needed
14.8
Squares
Architectural
Coverage: 32.8 sq ft/bundle
Weight: 65 lbs/bundle

Underlayment

4
Rolls Needed
3.7
Coverage Ratio

Additional Materials

Ridge Cap Shingles
40 ft ridge length
2 bundles
Starter Strip
Perimeter coverage
2 bundles

Total Weight

2925 lbs
(1.5 tons)

Cost Estimation

Shingles Cost:$5400
Underlayment Cost:$180
Labor Cost:$4696
Other Materials:$200
Total Project Cost:$10476
Cost per sq ft: $7.81

How to Use

1

Select your roof type and choose between entering dimensions or total area.

2

Enter your roof measurements, including length, width, and pitch if applicable.

3

Choose your shingle type, underlayment, and additional materials needed.

4

Enter material prices and labor rates to get a complete cost estimate.

Understanding Roofing Materials

Shingle Types

3-Tab Shingles

Basic asphalt shingles with uniform appearance. Most economical option with 20-25 year lifespan.

Architectural Shingles

Dimensional shingles with varied appearance. Better durability and 25-30 year lifespan.

Premium Shingles

High-end architectural shingles with enhanced features. 30-50 year lifespan.

Luxury Shingles

Designer shingles mimicking slate or wood. Premium appearance with 40-50 year lifespan.

Roof Measurements

Roof Pitch

The slope of the roof expressed as rise over run. Affects material requirements and installation difficulty.

Square

A roofing square equals 100 square feet. Industry standard unit for measuring roof area.

Waste Factor

Additional material needed for cuts, overlaps, and mistakes. Typically 10-15% of total area.

Installation Components

Underlayment

Water-resistant barrier installed under shingles. Felt paper or synthetic materials provide backup protection.

Ridge Cap

Special shingles that cover the peak of the roof. Provides weather seal at the ridge line.

Starter Strip

First course of shingles at the eave. Provides proper overhang and wind resistance.

Flashing

Metal strips that direct water away from roof penetrations and intersections.

Applications

Homeowners

  • • Roof replacement planning
  • • Material cost budgeting
  • • Contractor quote verification
  • • DIY project planning
  • • Insurance claim estimates

Contractors

  • • Job bidding and estimates
  • • Material ordering
  • • Project cost calculation
  • • Waste factor planning
  • • Client presentations

Professionals

  • • Architectural planning
  • • Construction estimating
  • • Building inspections
  • • Real estate assessments
  • • Educational purposes

Example Calculations

Small Ranch House

Dimensions: 30×40 ft, 4/12 pitch
Roof Area: 1,265 sq ft
Shingles: 14 bundles (4.2 squares)
Underlayment: 3 rolls
Estimated Cost: $3,800-$6,300

Large Two-Story Home

Dimensions: 40×60 ft, 8/12 pitch
Roof Area: 3,578 sq ft
Shingles: 40 bundles (11.9 squares)
Underlayment: 8 rolls
Estimated Cost: $10,700-$17,900

Frequently Asked Questions

How accurate are these calculations?

Our calculations provide accurate material estimates based on standard industry practices. However, complex roof designs may require professional measurement for precise quantities.

What waste factor should I use?

Use 10% for simple roofs, 15% for complex roofs with many angles, and 20% for very complex designs or if you're inexperienced with roofing installation.

How do I measure roof pitch?

Roof pitch is measured as rise over run. A 4/12 pitch means the roof rises 4 inches for every 12 inches of horizontal distance. You can measure this with a level and measuring tape.

Should I include gutters in my estimate?

This calculator focuses on roofing materials. Gutters, downspouts, and other accessories should be calculated separately based on the perimeter of your roof.