How this calculation works
Estimate sloped roof area from footprint, pitch, overhang, and roof form. The result is calculated locally in your browser from the visible inputs, and the method below remains available for checking.
Worked example
An 80 m² footprint at 30° has about 92.38 m² of slope area before overhang and waste.
Assumptions and limits
- Inputs use the units shown beside each field.
- Intermediate values retain precision; displayed values are rounded for readability.
Questions people ask
How does the Roof Area Calculator work?
It applies this displayed method: Sloped area = footprint including overhang ÷ cos(pitch); waste is added afterward. Values stay in your browser and are not submitted to a server.
What should I check before using the Roof area result?
Inputs use the units shown beside each field. Intermediate values retain precision; displayed values are rounded for readability. Quantities are planning estimates. Site conditions, product sizes, workmanship and structural specifications require professional verification.
Does this Roof area calculator save my information?
No. Calculation inputs are processed on this device. Sharing creates a URL only when you choose the share action.