Quick answer
Estimate roofing squares and shingle bundles from roof area, waste allowance and bundles per square. Use the working RenoMetric calculator below for the actual estimate, then use this page to check assumptions, package rounding and project-specific considerations.
Open the working Roofing calculator
Formula
Worked planning example
A 2,000 ft² roof is 20 roofing squares before waste. At three bundles per square, that is 60 bundles before allowance.
Common uses
- Asphalt shingles
- Roof replacement budgets
- Garage roofs
- Simple additions
How to get a better estimate
Measure the actual project rather than relying on listing dimensions. For irregular spaces, split the surface into simple measurable sections and add the results. Use the exact product label for package coverage, yield, density or square-foot coverage whenever it is available.
Keep waste and package rounding as separate steps. Waste covers cuts, breakage, pattern matching and unavoidable offcuts. Package rounding reflects the fact that many materials are sold only in complete bags, boxes, bundles or cans.
Before you buy: this page is a planning guide, not a contractor quotation or structural design. Verify final quantities with the product manufacturer, supplier or installer when project conditions could materially change the result.
Shingle Calculator FAQ
What is a roofing square?
One roofing square is 100 square feet of roof surface area.
How many bundles are in a square?
Many asphalt products use three bundles per square, but some use more. Check the exact product packaging.
How much shingle waste should I add?
Simple gable roofs may need less than complex hip-and-valley roofs. Use the roof geometry and installer guidance to choose the allowance.