Roof Shingle Area and Bundle Calculator
Calculate sloped roof area, cutting allowance and whole shingle bundles from footprint and coverage.
Formula
Planning estimate. Check product specifications and local requirements before purchasing.
Worked example: Roof Shingle Calculator
Measurements in this example
| Length | 10 m |
|---|---|
| Width | 8 m |
| Roof slope factor | 1.15 |
| Coverage per bundle | 3 m² |
| Waste allowance | 10 % |
Calculated quantities
| Area | 92 m² |
|---|---|
| Area with allowance | 101.2 m² |
| Whole bundles | 34 |
What to check
This calculation uses: Length, Width, Roof slope factor, Coverage per bundle, Waste allowance. It returns: Area, Area with allowance, Whole bundles.
Split the roof into simple slopes and measure each one. Valleys, hips, dormers and penetrations need separate allowance.
Flashing, underlay, ridge pieces, valleys, fasteners and drainage capacity are separate parts of the roof system.
Use the units beside each field. The values in the worked example are starting inputs; replace them with your measurements and the specifications of your material.
Compare alternatives
Open a tool, enter your measured dimensions, then save an estimate. Keep another version if you want to compare products or allowances.