Tile Calculator

Written byOleh Soloninupdated 25 September 2026

Area

Area to tile, m²

Tile width, cm

Tile height, cm

Joint width, mm

Spare, %

Advanced options

Tile thickness, mm

Tiles per box

Adhesive use, kg per m²

Take it from the adhesive bag for your trowel notch.

Grout density, kg per litre

From the grout bag: cement and epoxy grouts differ.

Result

Tiled area, m²12
Module area with joint, m²0.0912
With spare, m²13.2
Tiles145
Boxes14
Adhesive, kg60
Grout, kg2.05
How it was calculated
module with joint: (30 + 0.2) × (30 + 0.2) cm = 0.0912 m² 12 m² × (1 + 10%) = 13.2 m²; ÷ 0.0912 = 145 tiles grout: (30 + 30) ÷ (30 × 30) × 2 × 8 × 1.6 ÷ 10 × 12 = 2.05 kg

The joint is part of the module

Tile count allowing for joint width, how many boxes that is, and how much adhesive and grout the job will take.

Tiles go up with joints, so the unit to count is the module, not the tile: a 30 × 30 cm tile with a 2 mm joint occupies 30.2 × 30.2 cm, which is 0.0912 m². Over 12 m² with a 10% allowance that is 145 tiles. Ignoring the joints would give 147: the joint itself covers part of the area, and the gap widens with small tiles.

Adhesive and grout come from the bag rather than from a rule of thumb: adhesive use depends on the trowel notch, and the mass of grout depends on tile size, joint width and depth and the density of the mix. All three are input fields here.

How to use

Set the area: as a number, or from the room dimensions when you are tiling a floor or walls.
Enter the tile size and the joint width — together they form the module the count is based on.
Set the allowance, the adhesive rate from the bag and the grout density; read the number of tiles, boxes and the material weights.

Tiles, adhesive and grout by format

Every row is a separate run of this calculator with a 10% allowance, an adhesive rate of 5 kg/m² and a grout density of 1.6 kg per litre.

Every value was produced by the calculator on this page.
Area	Tile	Joint	Module	Tiles	Boxes	Adhesive	Grout
12 m²	30 × 30 cm	2 mm	0.0912 m²	145	14	60 kg	2.05 kg
5 m²	20 × 30 cm	2 mm	0.061 m²	91	9	25 kg	1.07 kg
20 m²	60 × 60 cm	2 mm	0.3624 m²	61	6	100 kg	1.71 kg
12 m²	30 × 30 cm	3 mm	0.0918 m²	144	14	60 kg	3.07 kg
12 m²	10 × 10 cm	2 mm	0.0104 m²	1,269	116	60 kg	6.14 kg

The joint cuts both ways

A wider joint means fewer tiles and more grout. The same 12 m² in 30 × 30 cm tiles: with 2 mm joints, 145 tiles and 2.05 kg of grout; with 3 mm joints, 144 tiles and 3.07 kg. One tile saved, half as much grout again.

A small format moves both numbers at once: 10 × 10 cm tiles over the same 12 m² come to 1,269 tiles and 6.14 kg of grout at the same 8 mm tile thickness, because there is three times as much joint length per square metre as with 30 × 30 cm. Small tiles are often thinner, and at 6 mm the grout drops to 4.61 kg.

What the Russian finishing code requires

SP 71.13330.2017 does not prescribe a joint width — the design does. Its table 7.6 of tolerances for cladding was deleted by Amendment No. 3 from 1 February 2026: clause 7.4.17 now says the customer's requirements must be met, so tolerances are agreed in the contract.

Clause 7.4.15 of the same code caps the adhesive layer at the thickness stated by the manufacturer. That is why the adhesive rate here is a field and not a constant: a 6 mm notch and a 10 mm notch are different jobs. Outside Russia the arithmetic still holds; the tolerances are set by your own national code.

What this calculator shows

Module area including the joint, and the resulting tile count
How many boxes that is at your pack size
Adhesive and grout in kilograms

What to keep in mind

Adhesive defaults to 5 kg per m²; the real rate depends on the adhesive and the trowel notch — it is printed on the bag, so enter it in the extra field.
Grout is estimated from joint volume at 1.6 kg per litre — the exact figure varies by manufacturer.

FAQs

How many tiles for a 5 m² bathroom?

In 20 × 30 cm tiles with 2 mm joints and a 10% allowance, 91 tiles — nine boxes of 11. At 5 kg/m² that is 25 kg of adhesive and about 1.07 kg of grout.

Why count modules rather than tiles?

Because on the wall a tile takes up more than its own size: 30 cm plus a 2 mm joint is 30.2 cm. Ignoring the joint would give 147 tiles for 12 m² instead of 145: two tiles out with 30 × 30 cm, but 51 with 10 × 10 cm mosaic, where the joint takes a larger share of each module.

How much adhesive per square metre?

Whatever the bag says for your trowel notch: it depends on the notch and on how flat the substrate is. SP 71.13330.2017 points to the manufacturer's documentation in clause 7.4.15, so the calculator takes that figure from you.

How much grout will I need?

It follows the volume of the joints: joint length per square metre times joint width and depth times the density of the mix. For 12 m² of 30 × 30 cm tiles with 2 mm joints, 8 mm thick, at 1.6 kg per litre, that is 2.05 kg.

How do I get the number of boxes?

Tiles divided by the tiles per box, rounded up. With 11 per box, 145 tiles is 14 boxes. The 145 already include the cutting allowance; the 154 tiles in 14 boxes add another 9 from rounding to whole boxes.

How much more does a small format cost?

Little in tiles, a lot in grout and labour: 10 × 10 cm over 12 m² needs 6.14 kg of grout against 2.05 kg for 30 × 30 cm at the same 8 mm thickness, and 1,269 tiles to lay instead of 145.

Worked example

A 12 m² bathroom

Input: 12 m², 30 × 30 cm tiles, 2 mm joints, 10% allowance

Output: 145 tiles, 14 boxes, 60 kg of adhesive, 2.05 kg of grout

Note: The module with the joint is 0.0912 m², and 13.2 m² has to be covered.

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