Roofing Calculator

Estimate sloped roof area and roofing squares from plan dimensions, pitch and waste allowance.

For a 6:12 roof, enter 6.

How it works

The calculator multiplies horizontal plan area by the slope factor derived from rise and run.

roof area = plan area × √(1 + (rise ÷ 12)²)

Limitations

  • Assumes a roof where the entered horizontal plan area represents the complete roof footprint; hips, valleys, overhangs and complex geometry require separate sections.