Waste first
Adjusted area = base area × (1 + waste percentage ÷ 100). Adjusted roofing squares = adjusted square feet ÷ 100.
Free roofing tool
Shingle Bundle Calculator
Estimate shingle bundles from roof area, waste and editable bundles-per-square coverage. See the raw calculation beside the whole-bundle purchase quantity.
Inputs
Enter area and shingle coverage
Use the area you have, then enter the packaging coverage for the product you plan to order.
Methodology and rounding
Raw versus purchase bundles
Raw bundles = adjusted squares × bundles per square. Purchase quantity uses the source rounding direction: round up to the next whole bundle.
The 3-bundle default is editable and not a manufacturer-specific claim. Verify package coverage, starter, ridge and accessory requirements before ordering.
Worked example
3,000 sq ft with 15% waste becomes 34.50 squares. At 4 bundles per square, the raw calculation is exactly 138.00 bundles and the purchase quantity is 138.
Shingle bundle calculator FAQ
How many bundles per square should I use?
The source defaults to 3, but packaging varies. Enter the exact bundles-per-square figure for the shingle product being priced.
Can I enter squares or square meters?
Yes. The calculator accepts square feet, roofing squares or square meters and converts through the same source factors.
Why round bundles up?
Bundles are purchased as whole units. The raw calculation stays visible, then purchase quantity is rounded upward with Math.ceil.
When is waste applied?
Waste is applied to roof area before multiplying by bundles per square, exactly once.