Understanding the topic
Tile estimates depend on the floor area, the size of each tile and the layout. Extra tiles are usually needed for cuts, breakage and future repairs. Always check the product’s coverage per box and the recommended allowance.
Quick reference
Use these reference points alongside the worked examples below.
| Term | Meaning / value | Why it matters |
|---|---|---|
| Room area | Length × width | Use metres for m² |
| Tile area | Tile length × width | Convert dimensions to metres |
| Tiles needed | Room area ÷ tile area | Round up to whole tiles |
| Box coverage | m² per box | Used to determine boxes |
| Allowance | Extra for cuts and waste | Higher for complex layouts |
Step-by-step method
- Measure the room and split irregular shapes into rectangles.
- Calculate total area in square metres.
- Find the tile size and box coverage on the packaging.
- Add a suitable cutting and breakage allowance for the layout.
- Round up to whole boxes and confirm batch availability.
Worked examples
Example 1: Floor area
A 3 m × 4 m room has an area of 12 m².
Example 2: Tile size
A 600 mm × 600 mm tile covers 0.6 × 0.6 = 0.36 m².
Example 3: Box count
For 12 m² plus 10% allowance = 13.2 m². At 1.44 m²/box, 13.2 ÷ 1.44 = 9.17, so buy 10 boxes.
Common mistakes and useful cautions
- Do not calculate using millimetres without converting units.
- Diagonal patterns and small offcuts may require more allowance.
- Tile boxes can differ in shade or batch; verify before ordering.
Practice questions
Try each question before revealing the answer.
Question 1: What is the area of a 2.5 m × 3 m floor?
Answer: 7.5 m².
Question 2: What is 10% extra on 20 m²?
Answer: 2 m² extra, making 22 m².
Question 3: Why round up the box count?
Answer: Tiles are usually sold in complete boxes.
What to remember
- Measure the room and split irregular shapes into rectangles.
- Round up to whole boxes and confirm batch availability.
- Do not calculate using millimetres without converting units.