Wall Tile Calculator — Tiles, Adhesive & Grout Needed

Our wall tile calculator works by calculating the total wall area to be tiled, subtracting any windows and doors, then dividing by the individual tile area. We add a waste allowance based on your chosen laying pattern and round up to complete boxes.

The formula

Tiles needed = (Net wall area ÷ Tile area) × (1 + Waste %)

For example, tiling 10 m² with 300×600mm tiles: 10 ÷ 0.18 = 56 tiles, plus 10% waste = 62 tiles. At 8 tiles per box, that's 8 boxes.

Adhesive and grout estimates

• Adhesive: A standard 20kg bag of flexible powder adhesive covers approximately 4-5 m² of wall tiles using a 6mm notched trowel (as per manufacturer guidelines from Weber, Mapei, and BAL). Large-format tiles (600mm+ side) need solid bedding with a 10-12mm trowel and back-buttering, which drops coverage to roughly 3 m² per bag. See the full table of tile adhesive coverage per square metre by trowel size for other tile sizes and substrates.
• Grout: Calculated based on tile size, joint width, and tile thickness. A 5kg bag of grout typically covers 5-15 m² depending on these factors.

Laying patterns

• Straight (Grid): 10% waste — simplest pattern with least cutting.
• Brick Bond (Offset): 10% waste — tiles offset by half, like brickwork. Most popular for metro tiles.
• Herringbone: 15% waste — tiles laid at 45° angles. More cuts required at all edges.

All calculations follow guidance from BS 5385-1 (wall tiling) and manufacturer coverage rates for adhesives and grouts commonly available in the UK (BAL, Weber, Mapei, Dunlop).