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🏠 Roofing Calculator

Estimate shingle bundles, roofing squares, underlayment, and material cost by roof type and pitch.

Enter Roof Dimensions

Your Estimate
Roofing Squares
—
squares (100 sq ft each)
Shingle Bundles
—
bundles (3 per square)
Roof Area
—
sq ft
Underlayment
—
sq ft

* Bundles assume standard 3-tab or architectural shingles (3 bundles per square). Verify bundle coverage with your specific product. Results are estimates only.

How to Use This Calculator

Enter your house's base length and width (the footprint, not the roof slope), select your roof type and pitch, choose your material, and hit Calculate. The calculator applies the pitch multiplier to find the true sloped area automatically.

For a hip roof, use the same length and width as the house footprint — the calculator handles the geometry.

Understanding Roofing Squares

A roofing square equals 100 square feet of roof area. It's the standard unit contractors and suppliers use. Most shingle packages cover one-third of a square, so you need 3 bundles per square.

Roof Area (sq ft) = Base Area × Pitch Multiplier × (1 + Waste Factor)
Squares = Roof Area ÷ 100
Bundles = Squares × 3

Roof Pitch Multipliers

A 6:12 pitch (rises 6 inches for every 12 horizontal inches) uses a multiplier of 1.118 — meaning a 1,000 sq ft footprint becomes 1,118 sq ft of actual roof surface. Steeper roofs need more material and are more expensive to install.

Roofing Cost in 2026

Asphalt shingles cost $90–$150 per square for materials. With labor, expect $350–$600 per square for full replacement. Metal roofing runs $300–$700 per square installed. Tile is $600–$1,500 per square. Always get 3 local quotes before committing.

Frequently Asked Questions

How many shingles do I need for a 1,500 sq ft roof?
A 1,500 sq ft roof needs 15 squares, or 45 bundles of standard architectural shingles. Add 15% waste for a total of about 52 bundles. Always round up to the nearest bundle.
What is the most common roof pitch?
In North America, 4:12 to 6:12 is the most common range for residential roofs. A 6:12 pitch is the sweet spot — steep enough to shed water and snow well, but easy enough for roofers to work on without safety equipment.
Do I need underlayment under shingles?
Yes. Building codes require underlayment (typically 15 or 30 lb felt, or synthetic) beneath all shingle roofs. It provides a secondary water barrier if shingles are damaged. Calculate the same square footage as your shingles.

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