Free calculator
Tile calculator: how many tiles do I need?
The tiles you need = the area ÷ the area of one tile plus its grout joint, rounded up, plus 10% for cuts. A 4 x 3 m floor in 30 x 30 cm tiles with a 3 mm gap is 131 tiles, 144 with waste. Enter your area, tile size and grout gap for the tiles and boxes to buy.
Result
- Area to tile
- 12 m²
- Tiles (exact)
- 131
- To buy with 10% waste
- 144
- Boxes
- enter tiles per box
Keep a few spare tiles from the same batch for future repairs; colours vary between batches.
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How it works
Each tile takes up its own size plus one grout joint along each side. Tiles = area ÷ ((tile length + grout) × (tile width + grout)). The tiles you need are that figure rounded up; the tiles to buy add the waste allowance to the exact figure and round up once.
Worked example: a 4 x 3 m floor is 12 m². A 30 x 30 cm tile with a 3 mm joint takes 0.303 x 0.303 = 0.0918 m², so 12 ÷ 0.0918 = 130.7, rounded up to 131 tiles. With 10% waste that is 144.
| Room | Tile | Tiles | With 10% |
|---|---|---|---|
| 10 x 10 ft (100 sq ft) | 12 x 12 in, 1/8 in grout | 98 | 108 |
| 10 x 10 ft (100 sq ft) | 12 x 24 in, 1/8 in grout | 50 | 55 |
| 10 x 10 ft (100 sq ft) | 16 x 16 in, 1/8 in grout | 56 | 61 |
| 12 x 12 ft (144 sq ft) | 12 x 12 in, 1/8 in grout | 142 | 156 |
| 12 x 12 ft (144 sq ft) | 16 x 16 in, 1/8 in grout | 80 | 88 |
| 4 x 3 m (12 m²) | 30 x 30 cm, 3 mm grout | 131 | 144 |
| 4 x 4 m (16 m²) | 30 x 30 cm, 3 mm grout | 175 | 192 |
| 4 x 4 m (16 m²) | 60 x 60 cm, 3 mm grout | 45 | 49 |
| 50 m² | 60 x 60 cm, 3 mm grout | 138 | 152 |
Ten percent waste is usual for a straight layout in a rectangular room. Use 15% for a diagonal or herringbone pattern, or for rooms with many corners and pipes. Large-format tiles waste more per cut, so keep the allowance even if the tile count is small.
Buy all boxes from the same batch number; shade and size can differ between batches. Keep a few spare tiles for future repairs.
Tile wastage: how much extra to buy
Tile wastage is the extra you order for cuts at the walls, broken tiles and pieces that do not match: the calculator starts at 10% and this page uses 15% for diagonal and patterned layouts. The table shows what each allowance means in tiles for the same floor, so you can see the cost of going up a step.
| Waste | 100 sq ft, 12 x 12 in | 100 sq ft, 16 x 16 in | 12 m², 30 x 30 cm |
|---|---|---|---|
| None | 98 | 56 | 131 |
| 5% | 103 | 59 | 138 |
| 10% | 108 | 61 | 144 |
| 15% | 113 | 64 | 151 |
| 20% | 118 | 67 | 157 |
Room by room: the shower tile guide does the walls of a shower, the backsplash guide a kitchen splashback, the 12x12 tiles for 100 square feet guide the larger floors, and tiles per square metre the metric sizes.
Frequently asked questions
- How many tiles do I need?
- Divide the area by the area of one tile plus its grout joint, round up, and add 10% for cuts and breakages. A 4 x 3 m floor in 30 x 30 cm tiles with a 3 mm gap: 12 ÷ 0.0918 m² = 130.7, so 131 tiles, 144 with waste. For walls, measure each wall and take off doors and windows first.
- How many 30 x 30 cm tiles do I need for 10 m²?
- With a 3 mm grout gap, about 109 tiles. With 10% waste, buy 120, which is 12 boxes of 10.
- How many tiles do I need for a 10x10 room?
- A 10 x 10 ft room is 100 sq ft: 98 tiles of 12 x 12 in with a 1/8 in grout line, 108 with 10% waste, or 113 with 15% for a diagonal layout. The table above has 12 x 24 in tiles and a 12 x 12 ft room.
- How many tiles do I need for a 4x4 room?
- A 4 x 4 m room is 16 m²: 192 tiles of 30 x 30 cm or 49 of 60 x 60 cm with a 3 mm gap and 10% waste (175 and 45 before waste).
- How many tiles do I need per square metre?
- 10.9 tiles of 30 x 30 cm or 2.75 of 60 x 60 cm per square metre with a 3 mm grout gap, before waste. The tiles per square metre guide below has the other common sizes.
- How many 12 x 12 inch tiles per square foot?
- One, before waste, if you ignore the grout gap; 0.98 with a 1/8 in grout line. For 100 sq ft with 10% waste, buy 110 with tight joints or 108 with a 1/8 in line.
- What is tile wastage?
- The tiles you buy on top of the exact count, for cuts, breakages and spares from the same batch. 10% on a straight layout turns 98 tiles of 12 x 12 in for 100 sq ft into 108; 15% for a diagonal makes it 113. The wastage table above has 0 to 20%.
- How many 16x16 tiles do I need?
- For 100 sq ft, 56 tiles of 16 x 16 in with a 1/8 in grout line, 61 with 10% waste. A 12 x 12 ft room (144 sq ft) is 80 tiles, 88 with waste. Each 16 x 16 tile with its joint covers 1.81 sq ft.
- How many boxes of tile do I need?
- Divide the tiles to buy (waste included) by the tiles per box on the label and round up. 100 sq ft of 12 x 12 in tiles is 108 tiles with 10% waste, so 11 boxes of 10. Enter the box size in the calculator and it does the division for you.
- What waste percentage should I use for tiles?
- 10% for straight layouts, 15% for diagonal or patterned layouts, and more for small or awkward rooms.
Guides
- How many tiles per square metre? 30x30, 60x60 and other sizes
Tiles per square metre for the common sizes with a 3 mm grout gap, how many to order for 10 m² with cutting waste, and when to allow more than 10%.
- How many 12x12 tiles for 100 square feet? (12x24, 18x18, 24x24 too)
Tiles needed for 100, 200, 300 and 500 sq ft in 12x12, 12x24, 18x18 and 24x24 inch sizes with a 1/8 inch grout line and 10% waste, and how to turn that into boxes.
- How many tiles do I need for a shower? 12x24, subway and 12x12
Wall area of 32x60, 36x36 and 36x48 in showers with 8 ft walls, tiles needed in 12x24, 3x6 subway, 12x12 and 2x2 mosaic sheets with 10 to 15% waste, and the floor on top.
- How many pavers do I need for a 10x10 patio? 12x12, 16x16, 24x24
Pavers for a 10x10, 12x12, 16x16 and 20x20 ft patio in 4x8, 6x9, 12x12, 16x16 and 24x24 inch sizes with a 1/8 in joint and 5% waste, plus the base to go under them.
- How many tiles for a kitchen backsplash? (subway, 4x12, mosaic)
Subway 3x6, 4x12 and 12x12 mosaic sheet counts for backsplashes of 10 to 30 linear feet at 18 inches high with 10% waste, boxes to order, and metric splashbacks.