How many tiles do I need? A bathroom wall example

Measure the area to be tiled

For an illustrative bathroom wall 2.4 m wide and 2 m high, the area is 2.4 × 2 = 4.8 m². Subtract a 1 m × 0.6 m window (0.6 m²) and the net area is 4.2 m². Measure each wall separately; bath panels and boxed-in pipes are easy to forget.

Divide by the tile size, then add wastage

A 300 × 600 mm tile covers 0.3 × 0.6 = 0.18 m². Without any allowance you would need 4.2 ÷ 0.18 = 23.3 tiles. Cuts around edges, the window reveal and the odd breakage add up, so a 10% allowance is a common starting point: 4.2 × 1.1 = 4.62 m², or 25.7 tiles — round up to 26.

Large-format tiles, diagonal layouts and patterned designs usually need a bigger allowance, often 15% or more.

Round to packs and keep spares

If the tiles come in packs of 6, 26 tiles means 5 packs, or 30 tiles. The four spare tiles are worth keeping: a later replacement from a different batch may not match in shade. Check grout and adhesive coverage on the product too.