Converts a measured area into the tiles and packs you have to buy, with the waste you choose.
Painting, tiling and finishes. 5 questions answered below, each with the arithmetic behind it and the limits of what the tool decides. Open the Tile Calculator tool.
A tiling estimate has three quantities that fail independently: tiles, adhesive and grout. Tiles fail when the waste allowance is too thin for the pattern, adhesive fails when the bed thickness is assumed rather than chosen, and grout fails when the joint width and tile size are not both known. The calculator holds all three together so a job is not ordered in three separate trips to the merchant. The mechanics are simple and unforgiving. Floor or wall area divided by the area of one tile gives the count, the layout pattern decides how much of that count is lost to cuts, and the tile size with the joint width decides how many square metres a bag of adhesive and a kilogramme of grout will serve. Because those relationships change with the pattern and the format, both stay as inputs you set, and the tool shows the square metres each bag covers rather than assuming one.
A bathroom floor is two and a half metres by two metres, so five square metres. With tiles of three hundred by three hundred millimetres, each tile covers nine hundredths of a square metre, which gives fifty six tiles before waste. Ten percent waste takes that to sixty two, and if the boxes hold eleven tiles you buy six boxes. The walls add eighteen square metres, and at three hundred by six hundred millimetres each tile covers eighteen hundredths of a square metre, so a hundred tiles, a hundred and ten with waste. Adhesive at four kilogrammes per square metre for a ten millimetre bed needs twenty kilogrammes for the floor and seventy two for the walls, so a twenty kilogramme bag and four more, not the single bag that a room count would suggest. Grout for a three millimetre joint on the floor needs roughly half a kilogramme per square metre, so two and a half kilogrammes, and the smaller wall tiles need more per square metre because the joints are denser.
Measure the floor or wall, then divide by the area of one tile, allowing for the joint if you want a close figure. The calculator does the division from the tile dimensions in millimetres or inches, so the count is in whole tiles and then converted to boxes. For a wall, measure each elevation separately and deduct the openings, because a room perimeter multiplied by height includes the door and window areas you are not tiling.
Because a tiled surface is not a rectangle. Edges need cuts, and cuts produce offcuts that cannot be used elsewhere. Tiles break in transit and on site, and a spare box left in the garage is what saves a matching problem when one cracks two years later. A straight lay in a large format needs around ten percent, a diagonal or herringbone layout needs fifteen or more, and the allowance is a percentage you set so it is visible in the total.
Adhesive follows the bed thickness and the coverage the product states, and grout follows the joint width, tile size and depth. The calculator asks for the coverage you are working to and multiplies it across the area, then converts to the bag size sold in your market. Grout is the one people underestimate: a small format tile with wide joints can consume several times the grout of a large format in the same area, so the calculator uses the geometry instead of a rate per square metre.
No. Buy the boxes the calculator shows, and keep the spare box. Tile production runs change shade, and a repair two years later needs a match that a new batch may not give. The boxes figure already includes the waste you set, so buying the raw area and hoping the cuts work out is how a job ends up one box short on a Friday afternoon.
Cuts at edges, breakages in transit and a spare for future repair are all waste, and waste is a percentage you control. Ten percent suits a straight lay, fifteen or more for a diagonal or herringbone, and more again for a room with many corners. It appears as its own line, so when a client asks why the order is larger than the floor area, the answer is a number on the page.