How to calculate tiles for a room (and how much wastage to add)

Step 1: measure the floor

Multiply the room's length by its width in feet to get the floor area. For L-shaped rooms, split the floor into rectangles and add them together.

Step 2: work out the area of one tile

A 600×600 mm tile covers about 3.88 sq ft; an 800×800 mm tile about 6.89 sq ft. Include the grout gap in the tile size for more accurate counts.

Step 3: add wastage for the pattern

Straight layouts need about 7% extra for cuts and breakage. Diagonal layouts need around 15%, and herringbone around 18%, because more tiles are cut at the edges.

Always buy a few extra tiles from the same batch — shades vary between batches, and you'll want spares for future repairs.

Step 4: convert to boxes

Divide the tile count by the number of tiles per box and round up. A 600×600 box usually holds 4 tiles; a 600×1200 box holds 2.