How Many Shingles for a 800 sq ft Roof at 6/12 Pitch
Calculate roofing shingles for an 800 sq ft roof (20×40 ft) with a 6/12 moderate pitch and 10% waste.
How to use this tool
- Enter the roof's horizontal length and width (one side) in feet.
- Set the pitch multiplier (6/12 pitch is about 1.12).
- Add a waste allowance of 10–15% for cuts around hips and valleys.
- The result shows total roof area, squares, and bundles to purchase.
A 20×40 ft roof with a 6/12 pitch is a standard moderate slope found on many colonial and cape-style homes.
Frequently asked questions
- What is a roofing square?
- A roofing square equals 100 square feet of roof surface. Standard shingles come in bundles, and 3 bundles cover one square.
- How many bundles of shingles per square?
- Most standard 3-tab or architectural shingles require 3 bundles per square (100 ft²). Heavy-weight shingles may require 4 bundles per square.