Tile Calculator
Work out how many tiles and boxes you need for floors or walls from area, tile size, grout gap, waste and price.
🔒 Runs entirely in your browser — nothing is uploadedHow the number of tiles is calculated
The calculator first measures the surface to be tiled. Each rectangle contributes area = length × width, and several rectangles are added together, which makes it easy to handle L-shaped rooms, alcoves or a floor plus a splashback. A waste allowance is applied on top: area with waste = area × (1 + waste ÷ 100). Waste covers cut tiles at the edges, breakage and mistakes, and it is larger for diagonal patterns or rooms with many corners.
Next comes the size of one tile. Because tiles are laid with a grout joint between them, each tile effectively covers its own size plus one gap in both directions: cell area = (tile length + gap) × (tile width + gap). The number of tiles is then tiles = ceil(area with waste ÷ cell area). For example, 12 m² with 10 % waste and 30 cm tiles with 3 mm joints gives 13.2 ÷ 0.303² ≈ 143.8, which rounds up to 144 tiles. The tool converts centimetres, millimetres, inches and feet consistently so you can mix the units that are natural for each measurement.
Boxes, cost and buying tips
Tiles are sold in boxes, so the number of boxes is ceil(tiles ÷ tiles per box). Because you must buy whole boxes, the estimated cost is boxes × tiles per box × price per tile, which is slightly higher than the exact number of tiles multiplied by the price. Always buy all tiles for one room in a single order, because shade and size can vary between production batches, and keep a few spare tiles in case a repair is needed years later.
These figures assume a simple straight-lay grid and do not include adhesive, grout, spacers or trim. Measure each wall or floor twice and check the actual tile dimensions on the box, since nominal and real sizes can differ. The calculator runs entirely in your browser, so your measurements and prices never leave your device.
How to use
- Add the areas to tileEnter the length and width of each rectangular area. Use Add area for L-shaped rooms or several surfaces.
- Enter tile size and grout gapType the tile length and width and the width of the grout joint between tiles.
- Set waste and box sizeAdd a waste percentage for cuts and breakage, and enter how many tiles come in each box.
- Read tiles, boxes and costSee the tiles needed, the boxes to buy and, if you entered a tile price, the estimated cost.