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Paint Calculator
Find out how many tins of paint you need.
Tile Calculator
Enter your floor or wall area, tile dimensions, grout gap width, and wastage percentage to calculate the total tile count and number of boxes to buy. Supports metric and imperial.
Room / area size (m)
Tile size (mm)
How to use the Tile Calculator
Choose metric or imperial
Select Metric (metres and millimetres) or Imperial (feet and inches) depending on your measuring tools.
Enter the room area
Measure and enter the length and width of the floor or wall to be tiled. For irregular shapes, divide into rectangles and add a room for each section.
Enter tile dimensions and grout gap
Enter the tile length and width (in mm or inches). Add the grout gap width — typically 3mm for wall tiles and 4–5mm for floor tiles.
Set wastage and box size
Enter a wastage percentage (10% for straight lay, 15% for diagonal) and the number of tiles per box from the product packaging. The calculator shows you exactly how many boxes to buy.
About this Tile Calculator
Tiling a floor or wall is one of the most rewarding DIY projects — and one of the most unforgiving if you run out of tiles halfway through. The challenge is that tiles come in boxes of fixed quantities, so you need to calculate the exact number and round up to whole boxes. The tiling calculation has several steps that are easy to get wrong manually: 1. **Area calculation**: length × width gives total area in square metres or square feet 2. **Tile pitch**: each tile occupies its own area plus a half-grout-gap on each side — so a 300mm tile with a 3mm joint occupies 303mm of space 3. **Tiles required**: total area ÷ tile pitch area gives the theoretical count 4. **Wastage**: cuts at the edges and breakages during installation mean you'll need extra tiles 5. **Box rounding**: always buy whole boxes — partial boxes can't usually be returned The wastage percentage matters. A straight horizontal and vertical lay needs about 10% extra. A diagonal (45°) or herringbone pattern requires more cuts, so 15% is safer. For unusually shaped rooms with lots of obstacles, corners, or cutouts, 15–20% is wise. One crucial tip: always check that tiles are from the same production batch (marked on the box) before you start. Slight colour variations between batches are common and only become visible when tiling is complete. Buy all your tiles at once from the same batch, and keep a few spare for future repairs.
Frequently Asked Questions
Divide the total area to be tiled by the area of one tile (including grout gap). Add a wastage percentage (typically 10% for straight lay, 15% for diagonal) for cuts and breakages. Our calculator does all of this automatically.
For a straight lay pattern, add 10% wastage. For a diagonal or herringbone pattern, add 15% as more cuts are required. For complex shapes or rooms with many obstacles (pipes, corners), consider 15–20%. It's always better to have a few extra tiles than to run short, as dye lots can vary between batches.
Standard floor tiles use a 3–5mm grout joint. Wall tiles typically use 2–3mm joints. Large-format tiles (600mm+) often use wider joints of 5–10mm to allow for slight warping. Mosaic tiles use 1–2mm joints. Check the tile manufacturer's recommendations.
Yes — always buy 10–15% more than your calculated amount. This covers cuts, breakages during installation, and future replacements if a tile cracks. Keep any leftover tiles as they're useful for repairs, especially since colours can vary between production batches.