Recommended Waste Factors
| Tile Pattern / Room Type | Waste % |
|---|---|
| Straight lay, simple room | 5–10% |
| Diagonal (45°) pattern | 15% |
| Complex cuts, L-shaped room | 10–15% |
| Herringbone or basket weave | 15–20% |
Tile Calculator
Calculate exactly how many tiles you need for any floor or wall project. Enter the room dimensions and tile size to get tile count, with waste percentage and estimated cost.
Tile Quantity Estimator
Frequently Asked Questions
How much extra tile should I buy?
A 10% waste factor is standard for simple straight installations. Add 15% for diagonal layouts or rooms with lots of cuts. Always buy an extra 5–10% beyond what you calculate to have spare tiles for future repairs. Dye lots can vary between production batches, making it difficult to match tiles purchased later.
How many tiles come in a box?
Tile boxes typically contain 10–20 tiles and cover 10–20 square feet, depending on tile size. Check the box for exact coverage. When purchasing, round up to full boxes and keep the extras — matching tiles for future repairs can be difficult if the line is discontinued.
Working out how many tiles
Tiles needed = area to cover ÷ area of one tile
Keep units consistent. For a 12 × 12 inch tile, each covers exactly 1 square foot, which makes the arithmetic easy. For a 300 × 600 mm tile, each covers 0.18 m².
Waste allowance
| Layout | Add |
|---|---|
| Straight / stacked | 10% |
| Brick or offset bond | 10–15% |
| Diagonal | 15% |
| Herringbone | 20% |
| Room with many cuts or angles | 15%+ |
Diagonal and herringbone layouts generate far more offcuts because almost every perimeter tile needs an angled cut, and the remainder is rarely reusable.
Buy the overage in one order
Tiles are produced in batches, and colour varies measurably between them. A second order weeks later may not match, which is obvious once laid — particularly on plain or light colours.
Keep a few spares after the job finishes. Tiles crack, and discontinued ranges cannot be matched at all.
Grout and adhesive
Grout quantity depends on tile size, joint width and joint depth. Small tiles with wide joints consume considerably more than large tiles with narrow ones — mosaic sheets can need several times the grout of a large-format tile over the same area.
Adhesive coverage depends on the notch size of the trowel, which in turn depends on tile size and substrate flatness. Larger tiles need a deeper notch and therefore more adhesive per square metre.
Before you order
Measure each wall or floor section separately rather than assuming the room is square, and subtract large permanent fixtures. Deduct openings only where they are substantial; small deductions tend to be absorbed by cutting waste anyway.