Flooring/Tile Calculator
Enter your room and tile dimensions, add a wastage allowance for cuts and breakage, and see exactly how many tiles — and boxes — to buy.
How Flooring/Tile Calculator Works
This calculator works out how many tiles to buy by comparing your room's total floor area against the area a single tile covers, then adding a wastage allowance to account for cuts, breakage, and offcuts that can't be reused.
Formula & Method
Room area is room length × room width. Tile area is tile length × tile width, converted into the same unit as the room (tile dimensions are entered in cm or inches, room dimensions in m or ft). The room area is inflated by your wastage percentage — area with wastage = room area × (1 + wastage% / 100) — and that figure is divided by the single-tile area, then rounded up to a whole number of tiles, since you can't buy a fraction of a tile. If you enter tiles-per-box, the tile count is divided by that and rounded up again to get the number of boxes to buy.
Worked Example
For a 5m × 4m room tiled with 60cm × 60cm tiles, a 10% wastage allowance, and 4 tiles per box: the room area is 20 m², and each tile covers 0.6m × 0.6m = 0.36 m². Adding 10% wastage brings the area to 22 m², and 22 ÷ 0.36 = 61.1, rounded up to 62 tiles. At 4 tiles per box that's 62 ÷ 4 = 15.5, rounded up to 16 boxes — which comes to 64 tiles actually purchased, giving an actual coverage of 22.32 m².
Frequently Asked Questions
- How much wastage allowance should I use?
- A straight/grid layout typically needs around 10% extra to cover cuts along the edges. A diagonal layout, a room with lots of corners and cuts, or a first-time DIY job (where breakage is more likely) usually needs 15–20% instead.
- Why are tile dimensions entered in cm (or inches) while the room is in meters (or feet)?
- That's the conventional way tiles are sized and sold, even though rooms are usually measured in larger units — the calculator converts both to the same unit internally before comparing areas, so you don't need to convert anything yourself.
- Why does the tile count round up instead of showing the exact decimal?
- Tiles are sold whole, and layouts always require some cutting at the edges, so 61.1 tiles needed becomes 62 tiles to buy — rounding down would leave you short.
- What if I don't know how many tiles come in a box?
- Leave "Tiles per Box" at 0. The calculator will still give you the total tile count and area coverage; it only calculates a box count when you provide a per-box quantity.
Tiles are conventionally sized in cm even when the room is measured in m — that's expected, not a mismatch. 10% wastage is typical for a straight/grid layout; bump it up to 15–20% for a diagonal layout or a room with lots of corners and cuts. Leave "Tiles per Box" at 0 if you don't need the box count.