How to Calculate Tiles for Walls and Floors
Start by measuring the total area you want to tile in square metres. For floors, multiply the room length by the width. For walls, measure the height and width of each wall section individually. Subtract any areas you will not tile, such as windows, doors or sections behind fitted furniture that will never be visible. Once you have the net area, divide it by the area of a single tile, including the grout gap, to get the number of tiles needed.
Always add a waste allowance on top of your calculated figure. For standard straight-laid patterns, 10 per cent extra is sufficient. If you are laying tiles diagonally, in a herringbone pattern or working with an irregular room shape, increase this to 15 per cent. Larger tiles produce fewer cuts but each wasted piece represents a bigger proportion of material, so the waste percentage remains similar regardless of tile size.
Choosing the Right Tiles for Your Space
Ceramic tiles are the most affordable option and come in a vast range of colours, patterns and sizes. They are ideal for walls and light-traffic floor areas. Porcelain tiles are denser and harder, making them better suited to busy floors, outdoor spaces and areas exposed to moisture. Natural stone tiles, including marble, slate and limestone, offer a premium look but require sealing and more careful maintenance. For kitchens and bathrooms, always choose tiles with an appropriate slip resistance rating.
The size of tile you choose affects both the visual appearance and practical aspects of your project. Larger format tiles such as 600 by 600 millimetres create a sense of space and have fewer grout lines to clean, but they require a very flat substrate and are heavier to handle. Smaller mosaic tiles are excellent for curved surfaces and decorative features but take significantly longer to install.
Budgeting for Adhesive, Grout and Labour
Beyond the tiles themselves, factor in the cost of adhesive, grout, a suitable primer, spacers and any waterproofing membrane needed in wet areas. Tile adhesive coverage is approximately 3 to 5 kilograms per square metre depending on tile size and the trowel used. Professional tiling labour in the UK ranges from 25 to 40 pounds per square metre, with intricate patterns and natural stone costing more.
Explore our paint calculator for adjacent surfaces, or use the flooring calculator if you are comparing tiled floors with other materials. For building regulations and home improvement guidance, visit GOV.UK.
This calculator provides estimates for guidance only. Actual tile requirements may vary depending on room shape, tile pattern, wastage and surface condition. This is not professional advice.