Roofing Calculator
Estimate roofing squares, shingle bundles and material cost based on your roof size and pitch.
This roofing calculator converts your roof's footprint dimensions and pitch into the actual surface area you need to cover, then translates that into roofing squares and bundles of shingles. Enter your roof length and width, choose your pitch, add a waste percentage for hips, valleys and complex cuts, and optionally add a price per bundle to estimate total material cost.
Your Estimate
Roof Footprint Area
1000.0 ft²
Actual Roof Surface Area
1118.0 ft²
Roofing Squares Required
11.18 squares
Bundles of Shingles Required
34 bundles
Bundles Including Waste
37 bundles
Surface area adjusted using a pitch multiplier of 1.118 (rise of 6/12). One roofing square equals 100 sq ft. Confirm shingle coverage and bundle count with your supplier before ordering.
Results Actions
Estimates are approximate. Actual shingle coverage varies by manufacturer, and complex roofs with multiple hips, valleys or dormers require additional material — always confirm with your roofing contractor before ordering.
Common Roof Pitches
Typical Asphalt Shingle Coverage
How to Use the Roofing Calculator
- 1Measure the length and width of your roof footprint (the building outline below the roof).
- 2Select your roof pitch from the dropdown, or choose Custom to enter your own rise per 12 units of run.
- 3Choose a waste percentage — 10% for a simple roof, 15%+ for roofs with hips, valleys or dormers.
- 4Confirm the bundles per square for your shingle type (most architectural shingles use 3).
- 5Optionally enter a price per bundle to see an estimated total material cost.
Example Calculation
Say you have a 40 ft x 25 ft roof footprint with a 6/12 pitch and a 10% waste factor. Footprint area = 40 × 25 = 1,000 ft². The pitch multiplier for 6/12 is about 1.118, so the actual surface area = 1,000 × 1.118 = 1,118 ft². Roofing squares = 1,118 ÷ 100 = 11.18 squares. At 3 bundles per square, that is 34 bundles (rounded up). Adding 10% waste brings the total to about 37 bundles to order.
Accuracy & Assumptions
- Results are estimates only.
- Actual shingle coverage varies by manufacturer and product line.
- Complex roofs with multiple hips, valleys or dormers require additional material beyond the standard waste allowance.
- Consider ordering an additional 5–10% beyond the calculated waste for cutting and damaged shingles.
- Consult a licensed roofing contractor before finalizing material orders.
Frequently Asked Questions
How many bundles of shingles do I need for a 2,000 sq ft roof?
With a 6/12 pitch, a 2,000 sq ft footprint has a surface area of about 2,236 sq ft, or roughly 22.4 roofing squares. At 3 bundles per square that is about 67 bundles, plus 10% waste brings it to around 74 bundles.
What is a roofing square?
A roofing square is a unit of measurement equal to 100 square feet of roof surface. Shingles, underlayment and other roofing materials are typically priced and sold by the square.
How does roof pitch affect material needs?
Steeper pitches have more actual surface area than the footprint below them. A 6/12 pitch adds about 12% more surface area than the flat footprint, while a 12/12 pitch adds about 41% more.
How many bundles of shingles come in a square?
Most architectural (dimensional) shingles use 3 bundles per square. Some three-tab shingles use 3 bundles per square as well, though certain heavier or specialty products may require 4 or 5 bundles per square — check your product packaging.
How much waste should I add for a roofing project?
Add 10% waste for a simple gable roof, and 15% or more for roofs with multiple hips, valleys, dormers or complex cuts.
This calculator provides an estimate for planning purposes only. Shingle coverage, bundle weight and manufacturer specifications vary — always confirm final quantities with your roofing contractor or supplier before purchasing.