Roofing Area and Material Calculator
Calculate sloped roof area with waste allowance from footprint dimensions and roof pitch.
Formula
Planning estimate. Check product specifications and local requirements before purchasing.
Worked example: Roofing Calculator
Measurements in this example
| Length | 10 m |
|---|---|
| Width | 6 m |
| Roof pitch | 30 ° |
| Waste allowance | 10 % |
Calculated quantities
| Area | 76.21 m² |
|---|---|
| Material units | 77 |
What to check
This calculation uses: Length, Width, Roof pitch, Waste allowance. It returns: Area, Material units.
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.