Tile Quantity Calculator
Calculate how many floor or wall tiles you need, including a 10% wastage buffer for cuts and breakages. Enter the room and tile dimensions to get your order quantity instantly.
About this calculator
The number of tiles required covers the floor or wall area divided by the area of a single tile, rounded up to the nearest whole tile, with an added 10% for wastage. The formula is: Tiles = ⌈(floorLength × floorWidth) / (tileLength × tileWidth)⌉ × 1.1. The ceiling function (⌈⌉) ensures partial tiles are counted as whole tiles since you cannot buy fractions of a tile. The 10% wastage buffer (multiplying by 1.1) accounts for cuts around edges and obstacles, breakages during laying, and keeping spares for future repairs. For diagonal or herringbone patterns, the wastage should be increased to 15% as more cuts are needed. All dimensions should be entered in the same unit — typically metres — to keep the calculation consistent.
How to use
You are tiling a kitchen floor 4 m long and 3 m wide using 0.3 m × 0.3 m tiles. Step 1 — Enter Floor Length = 4 m. Step 2 — Enter Floor Width = 3 m. Step 3 — Enter Tile Length = 0.3 m. Step 4 — Enter Tile Width = 0.3 m. Step 5 — Floor area = 4 × 3 = 12 m². Tile area = 0.3 × 0.3 = 0.09 m². Step 6 — Base count = ⌈12 / 0.09⌉ = ⌈133.33⌉ = 134 tiles. Step 7 — With 10% wastage: 134 × 1.1 = 147.4, so order 148 tiles.
Frequently asked questions
Why should I add a wastage allowance when calculating how many tiles to buy?
Even on a perfectly rectangular room, tiles along the edges almost always need to be cut to fit. Every cut produces an offcut that may not be reusable, and cutting also risks cracking or chipping tiles. A 10% buffer covers typical edge cuts and a small number of accidental breakages. Buying all tiles from the same batch is important because tile colour and shade can vary between production runs, making matching replacements difficult later.
How do I calculate tile quantity for a diagonal or herringbone pattern?
Diagonal and herringbone layouts require significantly more cuts because tiles must be trimmed at 45° angles along every wall edge. Increase your wastage allowance from 10% to 15% for a diagonal layout, and to 15–20% for herringbone. Enter the room dimensions and tile dimensions as normal, but multiply the ceiling result by 1.15 or 1.20 instead of 1.10 when placing your order. Complex feature areas such as alcoves and bay windows add further cut tiles.
What tile size works best for small versus large rooms?
Large format tiles (600 mm × 600 mm or bigger) create a seamless, open feel and have fewer grout lines, making them popular for open-plan areas. However, they require a very flat subfloor and are harder to cut around obstacles. Smaller tiles (e.g., 300 mm × 300 mm or mosaic sheets) are more forgiving on uneven floors and easier to cut around curved surfaces such as toilet bases and baths. As a general guideline, choose a tile size no larger than one-third of the shortest wall length to maintain visual balance.