Shingle Calculator

Enter the roof area or the footprint and pitch, set your waste allowance, and get the full order.

Works for three-tab and architectural shingles at three or four bundles per square.

How to use the shingle calculator

Why use the Build Tally shingle calculator

Bundles, squares and coverage

Shingles are packaged in bundles and sold by the square, which is 100 square feet of finished coverage. Most three-tab and architectural shingles come three bundles to the square; heavier designer and multi-layer profiles are four or five, so check the bundle before you order. Bundle weight matters practically as well — a bundle of architectural shingles is 65–80 lb, and getting eighty of them onto a roof is a job for a delivery boom rather than a ladder.

The accessories that get forgotten

Field shingles are only part of a roof order. Starter strip runs along the eaves and often the rakes; ridge cap covers every ridge and hip and is sold separately or cut from three-tab; drip edge goes at eaves and rakes; and ice-and-water shield is required at eaves in cold climates and in every valley. Nails run roughly 320 per square with four nails per shingle, more in high-wind areas where six-nail patterns are specified. All of these are priced separately and all of them are needed.

Waste and hip roofs

Ten percent covers a simple gable roof. Hip roofs cut every course at an angle along the hips, so 15% is a realistic minimum and complex roofs with dormers and valleys can exceed that. Ridge and hip lengths add up quickly on a hip roof too — a hip roof has more linear feet of cap than a gable of the same footprint. Keep a bundle spare at the end of the job: shingle colour varies between production runs and a repair with a matching bundle is worth having.

Read the guide: Roof Pitch Explained: Rise Over Run, Degrees and the Slope Factor