How many 300 × 300 tiles in a square metre?

One tile covers 0.09 m², so 1 ÷ 0.09 = 11.1 tiles, or 12 whole tiles for exactly 1 m². With a 3 mm joint, an example width, it is 10.9 tiles. For a room, multiply the area by 11.1 first and round up once.

How many 600 × 600 tiles in a square metre?

One tile covers 0.36 m², so 1 ÷ 0.36 = 2.8 tiles, or 3 whole tiles for exactly 1 m². With a 3 mm joint, an example width, it is 2.75 tiles, which is 2.8 to one decimal.

How many 300 × 600 tiles in a square metre?

One tile covers 0.18 m², so 1 ÷ 0.18 = 5.6 tiles, or 6 whole tiles for exactly 1 m². A 15.12 m² floor is 84 tiles, and 93 with BuildBatch's example 10% extra for cuts.

How do I work out how many tiles I need for a room?

Take the area to tile, add the allowance for cuts, divide by the area of one tile and round up once. A 15.12 m² floor with 10% extra is 16.632 m², which is 93 tiles of 300 × 600 mm. Boxes are counted from the m² on the box: see how many tiles do I need?

How many tiles in a square metre?

Divide 1 by the area of one tile in square metres: a 300 × 300 mm tile covers 0.09 m², so a square metre takes 11.1 of them, and a 600 × 600 mm tile covers 0.36 m² and takes 2.8. Round up once, on the whole area to tile, not on each square metre.

The sum

Tiles per m² = 1 ÷ the area of one tile in m². With the size in millimetres, that is 1,000,000 ÷ (width × height).

The area of one tile is its face, with no joint. Joints are in the last column below.

Eight sizes

Tile size	Area of one tile	Tiles per m²	Whole tiles for 1 m²	Tiles per m² with a 3 mm joint
100 × 100 mm	0.01 m²	100.0	100	94.3
150 × 150 mm	0.0225 m²	44.4	45	42.7
200 × 200 mm	0.04 m²	25.0	25	24.3
300 × 300 mm	0.09 m²	11.1	12	10.9
300 × 600 mm	0.18 m²	5.6	6	5.5
600 × 600 mm	0.36 m²	2.8	3	2.8
75 × 150 mm, brick-shaped	0.01125 m²	88.9	89	83.8
100 × 200 mm, brick-shaped	0.02 m²	50.0	50	47.8

The “whole tiles” column is for exactly 1 m². For a larger area, work out the whole area first and round up once at the end. For 15.12 m² of 300 × 600 mm tiles, 15.12 ÷ 0.18 = 84 tiles. Rounding up to 6 a m² first would give 6 × 15.12 = 90.72, which is 91 tiles.

The 3 mm joint is an example width, not the width for any tile: the tile’s own instructions give the joint. A joint makes each tile take a little more room, so a joint lowers the count. It is worked out as 1,000,000 ÷ ((width + 3) × (height + 3)). Use the exact size printed on your box.

From tiles to boxes

BuildBatch counts boxes, not tiles. It divides the area to tile, plus an allowance for cuts, by the m² one box covers, from the box, and rounds up to whole boxes. It does not count joints.

If a box gives the number of tiles and no area, the tiles times the area of one tile gives it: 8 tiles of 300 × 600 mm is 8 × 0.18 = 1.44 m². Where the box gives both, the m² on the box is the figure to enter.

A floor and a wall

Two rooms from the planner, each with the example 10% extra for cuts. The box is another example figure, 1.44 m², and no product’s.

	Floor	Wall to 1.2 m
The room	4.2 m × 3.6 m	4.2 m × 3.6 m, 2.4 m high, with a door and a window
Area to tile	15.12 m²	17.73 m²
With 10% extra	16.632 m²	19.502 m²
Tile	300 × 600 mm, 0.18 m²	100 × 200 mm, 0.02 m²
Tiles to cover the area	84	887
Tiles with the extra, rounded up	93	976
Boxes of 1.44 m² (from the planner)	12	14
Tiles in those boxes	96	1008

A 1.44 m² box holds 8 tiles of 300 × 600 mm or 72 tiles of 100 × 200 mm, so the boxes hold at least the tiles the sum asks for. The planner reached 12 and 14 boxes from the m², without counting a tile. A box with a different m² on its label gives a different number of boxes.

The wall counts the distance round the room times 1.2 m, less the door. The window comes off only when the tiles go to the ceiling. How many tiles do I need? has the sum.

What changes the answer

The joint. At 300 × 600 mm, 3 mm takes the count from 5.6 to 5.5 a m². The tile’s instructions give the width.
The allowance for cuts. 10% is BuildBatch’s labelled example for tiles laid straight. A diagonal or herringbone layout, or large tiles in a small room, waste more: see wastage allowance explained.
The size on the box. A box’s tile size and its m² decide the count, so copy them from the box you will buy, not from the table.

Do it with BuildBatch

Open the tile calculator, type the room, say how high the tiles go and copy what one box covers from the box. It gives the whole boxes, and with them the number of tiles is the boxes times the tiles on the box’s label. For a floor, choose Flooring, then Tiles in the room refresh planner. Adhesive and grout are counted in how much tile adhesive and grout do I need?

What this guide does not cover

Mosaic tiles on sheets. Tiles laid in a pattern, where the layout decides the count. Which size suits a room. How to set out the rows, which the tile’s instructions give.