How Many Tiles Do I Need? Chart by Tile Size and Room

Divide the area by the size of one tile plus its joint, then add about 10% for cuts and breakages. A 10 × 12 ft floor in 12 × 12 in tiles with ⅛ in joints takes 130 tiles with 10% extra. In metric, a 3 × 2.5 m floor in 300 × 300 mm tiles with 3 mm joints takes 90 tiles.

Smaller tiles mean more joints per square metre, so mosaics need far more grout than large tiles.

Tiles per square foot and per 100 sq ft

Tiles with ⅛ in joints: per square foot, and for 100 sq ft with 10% extra
Tile	Per sq ft	100 sq ft, exact	100 sq ft + 10%
4 × 4 in	8.46	846	931
6 × 6 in	3.84	384	423
12 × 12 in	0.98	98	108
12 × 24 in	0.49	49	55
18 × 18 in	0.44	44	49
24 × 24 in	0.25	25	28

Metric: tiles with 3 mm joints, per m² and for 10 m² with 10% extra
Tile	Per m²	10 m², exact	10 m² + 10%
100 × 100 mm	94.3	943	1037
200 × 200 mm	24.3	243	267
300 × 300 mm	10.9	109	120
300 × 600 mm	5.5	55	61
600 × 600 mm	2.8	28	31
600 × 1200 mm	1.4	14	16

Tiles for common floor sizes

Tiles for a floor, with ⅛ in joints and 10% extra
Floor	12 × 12 in	12 × 24 in	24 × 24 in
5 × 8 ft	44	22	11
8 × 10 ft	87	44	22
10 × 12 ft	130	65	33
12 × 12 ft	156	78	40
12 × 16 ft	207	104	53

How much extra tile?

clé tile says the usual advice is to order 10% more tile than your measurements show, and 15% for a diagonal layout; Flooring Clarity gives 5–7% for straight layouts in simple rooms and 10–15% for diagonal and complex patterns. The calculator uses 10% unless you change it. Keep a few spare tiles from the same batch for repairs: colours vary between production runs.

Worked example: a 10 × 12 ft kitchen floor

Area: 10 × 12 = 120 sq ft.
Each 12 × 12 in tile plus a ⅛ in joint takes 12.125 × 12.125 = 147 sq in, so 120 sq ft (17,280 sq in) holds 117.5 tiles.
Add 10%: 129.3, so 130 tiles. Laid diagonally with 15% extra: 136.

In metric, if a box of 300 × 300 mm tiles holds 11 tiles (about 1 m²), the 3 × 2.5 m floor's 90 tiles come to 9 boxes. Check the count on your own box: it varies by product.

The tile calculator works this out for several areas at once, and adds the grout; for grout on its own, see how much grout you need.

Measuring for tiles

Floors: measure wall to wall, and split L-shaped rooms into rectangles. Leave out areas under fixed cabinets or a bath if you won't tile there.
Walls: width × height of each wall to be tiled, less windows and doors. Tiled splashbacks and shower walls are often a different tile, so count them separately.

Common mistakes

Using the nominal size. A "12 × 12" tile may measure slightly less. Measure one, or use the size printed on the box.
Buying exactly the area. Every cut at a wall wastes part of a tile, and some tiles break.
Buying in two batches. Tiles from different batches can differ in shade and size, so buy everything at once.