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
- 6 m
- Width / height
- 4 m
- Quantity
- 1
- Price per m² (optional)
- £0
the result is:
- Area
- 24 m²
- Square feet
- 258.3 sq ft
- Hectares
- 0.0024
- Square yards
- 28.7
Tips from the trade
- Split odd rooms into rectangles and triangles, work each out, and add them up.
- 1 m² = 10.764 sq ft. 1 hectare = 10,000 m².
Common questions
How do I calculate square metres?
Multiply length by width in metres. A 4 m × 3.5 m room is 14 m².
Results are estimates for planning and pricing. Check quantities against your drawings, the manufacturer’s data and the Building Regulations before ordering.