Wall & Floor Tile Calculator
Calculate tiles, adhesive bags and grout for any wall or floor. Covers all standard tile sizes with lay patterns, pack counts and grout joint width. 2026 UK pricing.
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Straight grid is the most economical pattern with fewest cuts and 10% waste allowance.
0.9×2.0m each
1.2×1.0m each
Enter to get pack count. Usually printed on the box.
Tiling Guide
Adhesive, Grout & Preparation
Choosing the right adhesive
Wall tiles: use a non-slip wall tile adhesive or ready-mixed adhesive. Standard coverage is 4–5 m² per 20kg bag using a 6mm notched trowel. Floor tiles: always use a cementitious powder adhesive — never ready-mixed for floors. Use flexible S1 adhesive for underfloor heating, wet rooms, or any area subject to movement. S2 adhesive for large format tiles over 600mm.
Large format tiles (over 600mm): reduce coverage assumption to 3 m²/20kg bag as you need a larger notch trowel (10–12mm) and must back-butter each tile. The combined bed + back-butter method ensures full coverage with no voids beneath large tiles.
Grout selection and quantity
Joint width determines grout type: joints up to 3mm use unsanded (fine) grout; 3–10mm use standard sanded grout; 10mm+ use wide-joint grout or pointing mortar. Epoxy grout is available for hygienic or chemical-resistant applications (commercial kitchens, laboratories) but is significantly more expensive and harder to apply.
Grout quantity formula: kg/m² = (tile_w + tile_h) ÷ (tile_w × tile_h) × joint_width × tile_thickness × grout_density. Typical grout density is 1.6–1.8 kg/litre. Our calculator uses this formula with a 10% buffer for waste.
Surface preparation
Walls: remove loose paint, dust and any residue. Fresh plaster must be fully cured (minimum 4 weeks) and primed with a dedicated tile primer — not PVA. Plasterboard must be sealed with tile primer before tiling. Painted walls must be tested for adhesion; glossy paint should be abraded.
Floors: must be flat to within 3mm in 3m (BS 8203). Sand and cement screeds must be fully cured and have a moisture content below 75% RH. Timber floors need a 6mm cement board overlay to prevent flex cracking the tiles. Never tile directly onto chipboard or suspended timber without a cement board layer.
FAQ
Common Questions
10% for standard straight or brick-pattern tiling in a regular rectangular room. 15% for diagonal or herringbone patterns. 15% for rooms with many obstacles. Always order all tiles at once from the same batch — colour and size can vary slightly between batches.
Rectified tiles (factory-cut to precise dimensions): 1–2mm. Standard ceramic wall tiles: 2–3mm. Floor tiles: 3–5mm. Natural stone with uneven edges: 5–10mm. Large format tiles: typically 3–5mm. Always check the tile manufacturer's recommendation — some tiles require a minimum joint width.
Always tile walls first, then floor. This prevents damage to floor tiles during wall tiling. Leave a small gap between the bottom wall tile course and floor tiles — fill with flexible silicone sealant, not grout. Silicone accommodates differential movement between wall and floor surfaces.
Standard tiles (under 600mm): approximately 4–5 m² per 20kg bag with a 6mm notched trowel. Large format tiles (600mm+): approximately 3 m² per 20kg bag — you need a larger notch and must back-butter. Our calculator estimates bags from your area, tile size and application type.
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