How this calculator works
The plan area is multiplied by √(1+(rise/12)²), adjusted for waste, then divided by 100 square feet per roofing square.
Formula
squares=(plan area×√(1+(rise/12)²)×(1+w/100))/100Roofing squares (100 ft² each) for a simple gable-equivalent roof using plan area, pitch and waste.
Worked example
Verified example is a verified test case used by the calculation engine.
Assumptions and limitations
- Building dimensions are entered in feet.
- Pitch is rise per 12 units of run.
- The model uses plan area × slope factor as a simple symmetric gable-equivalent estimate and does not add overhangs, hips, valleys, dormers or other roof complexity.
Methodology & sources
This calculator uses deterministic, versioned calculation logic. The formula and verified examples above are part of the calculation definition used by CalcuMint. Technical calculation version: 1.
- NIST SI Guide — Supports consistent dimensional and SI-unit treatment for geometric calculations.
Frequently asked questions
What is a roofing square?
In this calculator, one roofing square represents 100 square feet of roof area.
Does this model complex roofs?
No. It is a simplified plan-area and pitch model; complex geometry should be measured separately.