How the calculation works
The formulas
This area estimate uses a repeating slab-and-joint module. Actual tile-face purchase area can be smaller than the paved surface because joints occupy space. Check boundary cuts separately.
Module area = (slab length + joint) × (slab width + joint)
Slabs = ceil(area ÷ module area × (1 + waste/100))
Purchase face area = slabs × slab length × slab width
Assumptions to check
- Only aligned rectangular slabs are modelled; no border course or optimized layout is included.
- Base layers, drainage, excavation, and jointing materials are separate quantities.
A worked example
20 m² with 0.5 × 0.5 m slabs, no joints, and 10% waste requires 88 slabs, covering 22 m² of slab faces.