Roofing Calculator

Calculate shingles and materials based on roof area

Project Details
Enter your measurements and requirements
Results
Calculated estimates for your project
Roof Area0 sq ft
Squares0
Shingle Bundles0
Underlayment Rolls0

Additional Information

About This Roofing Calculator

Our roofing calculator helps you determine how many shingles, squares of roofing, and rolls of underlayment you need for your roof replacement or new construction. The calculator accounts for roof pitch to provide accurate material estimates for sloped roofs.

Roofing materials are sold in "squares" - one square covers 100 square feet. The calculator converts your roof dimensions and pitch into squares needed, then calculates shingle bundles (typically 3 bundles per square for standard 3-tab or architectural shingles).

This tool is designed for homeowners getting roofing estimates, DIYers planning a roofing project, and anyone asking "how many shingles do I need for my roof?" Remember that roofing is dangerous work - consider hiring professionals for steep roofs or if you're uncomfortable at heights.

How to Use This Calculator

Follow these steps to calculate your roofing materials:

  1. Measure your roof's length and width (the footprint, not actual surface)
  2. Determine your roof pitch (rise over 12 inches of run)
  3. Review the calculated roof area accounting for slope
  4. Note the number of squares and shingle bundles needed
  5. Add 10-15% extra for waste, especially for complex roofs
Frequently Asked Questions

How many bundles of shingles do I need?

Standard asphalt shingles require 3 bundles per square (100 sq ft). A typical 1,500 sq ft roof needs about 45 bundles. Architectural shingles may vary - some heavier products require 4-5 bundles per square. Always check the manufacturer's coverage specifications on the bundle wrapper.

How do I measure roof pitch?

Roof pitch is expressed as rise over run - a 6/12 pitch rises 6 inches for every 12 inches of horizontal run. To measure, place a level on your roof, mark 12 inches along it, then measure the vertical distance from that point down to the roof surface. Common pitches are 4/12 to 12/12.

How much does a new roof cost?

Asphalt shingle roof replacement typically costs $5,000-15,000 for an average home. Materials cost $100-150 per square for standard shingles, $150-250 for architectural. Labor adds $150-300 per square. Metal, tile, and slate roofs cost significantly more. Get multiple quotes and check contractor references.

Do I need underlayment for my roof?

Yes, underlayment is required under all shingle roofs. Felt paper (15lb or 30lb) is traditional and economical. Synthetic underlayment is stronger, lighter, and more water-resistant but costs more. Ice and water shield is required in valleys, around penetrations, and along eaves in cold climates.

How long do asphalt shingles last?

3-tab shingles typically last 15-20 years, architectural shingles 25-30 years, and premium architectural 30-50 years. Actual lifespan depends on climate, ventilation, installation quality, and color (darker colors absorb more heat). Get shingles with the longest warranty your budget allows.

Should I remove old shingles or roof over them?

Removing old shingles (tear-off) is generally recommended - it lets you inspect the deck for damage and provides a better surface for new shingles. Roofing over is only allowed for one layer and may void warranties. Building codes in many areas limit total roof layers to two. Always remove if there's damage or moisture issues.

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