Roofing Shingle Calculator: Squares and Bundles

How to do it

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   Step 1: Open Roofing Shingle Calculator: Squares and Bundles and add your input

   Type your numbers or text, add your file, or pick the options you need. Nothing is uploaded: everything stays in your browser.

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   Step 2: What Roofing Shingle Calculator: Squares and Bundles does

   Calculate roofing squares and bundles of shingles from the footprint and the roof pitch.

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   Step 3: Read the result and compare

   The result appears at once. Change one value to see how the answer moves, then keep the figure that fits your case.

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   Step 4: Copy or save it

   Copy the result or download it. For an important decision, confirm it with the official source or an adviser.

About this tool

Enter the footprint of the roof in square feet, the pitch as rise per 12 inches of run, a waste allowance and the ridge length. The calculator corrects the area for the slope, gives the squares, bundles of shingles, rolls of underlayment and the ridge cap bundles.

Slope correction

A sloped roof is larger than its footprint. The pitch factor is √(1 + (rise ÷ 12)²): 1.118 for a 6/12 roof and 1.414 for a 12/12 roof.

Squares and bundles

One roofing square covers 100 square feet and takes three bundles of standard shingles. Add 10% for waste, more on roofs with many valleys and hips. Underlayment rolls cover about 400 square feet. Ridge cap bundles cover about 20 linear feet each.

Check

Measure real roof areas where you can. Starter strips, drip edge, vents and flashing are extra.

Worked example

A 1,800 ft² footprint with a 6/12 pitch has a roof area of 2,012 ft², which with 10% waste is 22.1 squares or 67 bundles, plus 6 rolls of underlayment.

Tips for best results

Check every box before you rely on a result, because one wrong digit changes the whole answer. Use the exact figures from your payslip, bill, certificate or contract, and keep a note of the date you calculated. Rates, thresholds and rules change from time to time, so for tax, fees and legal matters treat the output as an estimate and confirm with the official source named on this page. You can run as many scenarios as you like; nothing is saved or sent, and refreshing the page clears the boxes.