Roof Area Calculator
Estimate true sloped roof area from plan footprint and roof pitch.
Step 1: Units
Step 2
Enter project measurements
Use decimals if needed (e.g. 3.5).
Step 3
How to use this calculator
Enter footprint area and pitch value to calculate total roof surface.
What the math is doing
Identical slope factor math as the roofing calculator.
Frequently asked questions
Measured plans?
Use plane areas from CAD if available.
Multi-level?
Sum each roof level.
Parapet walls?
Exclude wall tops unless they receive roofing.
Drip edge?
Linear feet of perimeter is separate.