Tile Calculator
Enter your room and tile dimensions and we calculate tiles needed (with wastage), boxes to order and total cost. Mix metric and imperial freely.
Total cost
£210.00
- Room area (m²)
- 12
- Tiles needed (with wastage)
- 37
- Boxes to buy
- 7
Tiles needed = ceil(room area ÷ tile area × (1 + wastage%)). Boxes round up to whole boxes; wastage covers cuts and breakages (10% straight lay, 15–20% diagonal).
How to use this calculator
Enter the room’s length and width and pick the unit (m, cm, ft or in). Enter your tile size and unit — ceramic tiles are commonly given in cm, US tiles in inches. Set wastage %: 10% for straight lays in simple rectangular rooms, 15% for cut-heavy layouts, 20% for diagonal or herringbone. Enter tiles per box and the price per box from the supplier listing.
How the calculation works
Both rooms and tiles are converted to square metres internally so units always agree. Tiles needed = ceil(room area ÷ tile area × (1 + wastage%)). Boxes are rounded up to a whole number, then total cost = boxes × price per box. The ceiling on tiles guarantees you have enough — you can’t buy 0.7 of a tile.
Worked example
A 4 m × 3 m kitchen with 60 × 60 cm tiles, 10% wastage, 6 tiles/box at £30: room area 12 m², tile area 0.36 m² → 33.33 tiles before wastage → ceil(33.33 × 1.10) = 37 tiles → ceil(37 ÷ 6) = 7 boxes → 7 × £30 = £210.
Frequently asked questions
How much wastage should I add for tiles?
For a simple rectangular room with a straight (grid) tile lay, 10% is the industry standard. For rooms with lots of cuts — awkward corners, alcoves, around fixtures — use 15%. For diagonal or herringbone patterns, use 20%. Always round up rather than down: an extra box costs less than a half-day delay waiting for stock.
Can I mix metric and imperial?
Yes. The room and tile inputs each have their own unit selector. So you can enter the room in feet and the tile in centimetres (or any other combination) — conversions happen behind the scenes via exact factors (1 ft = 0.3048 m, 1 in = 0.0254 m).
Why does the tile count round up?
You can’t buy a fractional tile. If the math says you need 33.4 tiles after wastage, the calculator rounds up to 34. Boxes are rounded up the same way — if you need 34 tiles and a box has 6, you need ceil(34 / 6) = 6 boxes (36 tiles).
Does this work for walls as well as floors?
Yes. Length × width gives an area whether the surface is horizontal or vertical. For a wall, "length" is the wall width and "width" is the wall height. For multiple walls, calculate each separately and sum the box counts (or sum the areas, but use the same wastage % across).
What about grout, adhesive and trims?
This calculator covers tile quantity and tile cost only. Adhesive coverage depends on the tile size, substrate and trowel notch — typically 4–6 m² per 20 kg bag for floor tiles. Add grout, primer, edge trim and labour separately.
How accurate is this for irregularly shaped rooms?
For rectangular rooms, very accurate. For L-shapes, split the room into rectangles, calculate each and sum tiles needed (then round up boxes once at the end). For very irregular shapes, increase wastage to 15–20% to absorb extra cuts.