About this calculator
Area for the shapes you meet on site, with conversions and an optional price per unit area.
How it’s calculated
Rectangle: L × W. Circle: π × r². Triangle: ½ × base × height. Trapezoid: ½ × (a + c) × height. L-shape: the full rectangle minus the cut-out.
Worked example
With these inputs:
- Shape
- Rectangle
- Length / base / diameter
- 20 ft
- Width / height
- 15 ft
- Quantity
- 1
- Price per sq ft (optional)
- $0
the result is:
- Area
- 300 sq ft
- Square yards
- 33.33
- Square metres
- 27.87 m²
- Acres
- 0.0069
Tips from the trade
- Split odd rooms into rectangles and triangles, work each out, and add them up.
- 1 sq yd = 9 sq ft. 1 m² = 10.764 sq ft.
Common questions
How do I calculate square footage?
Multiply length by width in feet. A 12 ft × 15 ft room is 180 sq ft.
Results are estimates for planning and pricing. Check quantities against your drawings, the manufacturer’s data and local building codes before ordering.