How the calculation works
The formulas
The area method divides surface area by tile-face area. The layout method counts rows and columns with joints and assumes every cut tile consumes a new tile. Choose which estimate drives purchasing.
Area tiles = ceil(surface area ÷ tile face area)
Columns = ceil((surface length + joint) ÷ (tile length + joint))
Rows = ceil((surface width + joint) ÷ (tile width + joint))
Boxes = ceil(ceil(base tiles × (1 + waste/100)) ÷ tiles per box)
Assumptions to check
- A rectangular aligned layout is assumed; offcut reuse, diagonal layouts, and movement joints are not designed.
- Purchase area uses whole boxes and actual tile faces, excluding joint area.
A worked example
A 4 × 3 m surface with 600 × 600 mm tiles and 3 mm joints has a 7 × 5 grid: 35 tiles. With 10% waste and 4 tiles per box, buy 10 boxes (40 tiles).