Calculator
Calculator for adhesive and grout consumption for wall and floor tiles
Enter the area, tile format, and joint size. The calculator will determine how many kilograms of adhesive and grout you need and how many bags and packages to buy. Adhesive calculations are based on the technical data sheet for Ceresit CM 11 Plus, and grout based on Mapei's formula.
Enter the data
Result
Format from 60 cm: use the combined method – adhesive on the back of the tile as well. Consumption will be higher than indicated by the calculation. Use flexible adhesive C2TE S1.
Joint wider than 8 mm: Ceresit CE 40 is for joints up to 8 mm. For wider joints, choose grout for up to 20 mm, such as Mapei Ultracolor Plus or Ceresit CE 43.
Joint narrower than 2 mm: Mapei Ultracolor Plus is for joints from 2 mm. For a narrow joint, refer to the technical data sheet of the grout.
Adhesives and grouts at vkupelni.sk ↗
Approximate calculation based on the technical data sheets for Ceresit CM 11 Plus and Mapei Ultracolor Plus. The consumption of specific adhesive is stated on the bag.
How the calculator calculates adhesive
Adhesive consumption mainly depends on the size of the tile. A larger tile requires a thicker layer of adhesive, which is why adhesive is applied with a trowel with deeper notches. The calculator takes the longer side of the tile and consumption according to the table from the technical data sheet for Ceresit CM 11 Plus:
| Longer side of the tile | Trowel notches | Adhesive consumption |
|---|---|---|
| up to 10 cm | 4 mm | 2,0 kg/m² |
| up to 15 cm | 6 mm | 2,7 kg/m² |
| up to 25 cm | 8 mm | 3,4 kg/m² |
| up to 30 cm | 10 mm | 4,2 kg/m² |
| over 30 cm | 12 mm | 4,8 kg/m² |
The manufacturer warns that actual consumption depends on the evenness of the substrate and the size and type of tiles. On uneven substrates, more adhesive is needed, so the calculator may add a 10% reserve. Adhesive is sold in paper bags of 25 kg, so the result is rounded to whole bags.
For larger formats and natural stone, the technical data sheet recommends the combined method: adhesive is applied with a notched trowel to the substrate and a thin layer to the back of the tile. This prevents voids under the tile, but consumption is higher than indicated in the table. For porcelain stoneware tiles, the adhesive should cover at least 70% of the back of the tile.
How to calculate grout
More grout is needed for smaller tiles (more joints per m²) and for wider and deeper joints. Mapei in the technical data sheet for Ultracolor Plus provides this formula:
Example: floor tiles 60 × 60 cm with a thickness of 9 mm and a grout joint of 2 mm → (600 + 600) ÷ (600 × 600) × 9 × 2 × 1.6 = 0.096 kg/m². For 20 m² of flooring, approximately 2 kg of grout is sufficient. Mosaic 10 × 10 cm with a grout joint of 3 mm requires nearly eight times more for the same area.
Other manufacturers use the same formula with a different number at the end based on the density of the grout. JUB states it with dimensions in centimetres and the number 15, which corresponds to 1.5 in millimetres – the result will be about 6% lower. The calculator uses a higher number to ensure grout is not lacking.
Examples for 20 m²
Consumption without reserve for standard tile thickness. The width of the grout joint is determined by the rectification of the tile and the manufacturer's recommendation for the wall tiles.
| Format | Grout joint (width × depth) | Adhesive | Grout |
|---|---|---|---|
| 15 × 15 cm | 3 × 8 mm | 54 kg (3 bags) | 10,2 kg |
| 30 × 30 cm | 2 × 8 mm | 84 kg (4 bags) | 3,4 kg |
| 30 × 60 cm | 2 × 9 mm | 96 kg (4 bags) | 2,9 kg |
| 60 × 60 cm | 2 × 9 mm | 96 kg (4 bags) | 1,9 kg |
| 20 × 120 cm (wood) | 2 × 9 mm | 96 kg (4 bags) | 3,4 kg |
| 60 × 120 cm | 2 × 9 mm | 96 kg (4 bags)* | 1,4 kg |
* For the format 60 × 120 cm, it is adhered using a combined method, so more adhesive will be needed. With a 10% reserve, for formats over 30 cm, it will be 105.6 kg, or 5 bags.
Which adhesive and grout to choose
For standard porcelain stoneware, a cement adhesive of class C2T is sufficient. For large formats from 60 × 120 cm, for underfloor heating, and where the substrate moves, flexible adhesive C2TE S1 is used. Grout for the bathroom should be water-repellent, class CG2 according to STN EN 13888. Ceresit CE 40 Aquastatic is for joints up to 8 mm, Mapei Ultracolor Plus is for joints from 2 to 20 mm, and both are sold in 2 and 5 kg bags. All abbreviations on the bags are explained in the article Adhesive, grout and trims for wall tiles.
How to avoid mistakes
- Level substrate – every millimetre of unevenness means more adhesive. Clean and prime the substrate before adhering.
- Correct trowel – choose the teeth according to the format from the table. Shallow teeth on large tiles will leave voids underneath.
- Mix in parts – mixed adhesive Ceresit CM 11 Plus can be processed for approximately 2 hours.
- Clean and deep joints – Mapei states that joints should be clean and empty at least two-thirds of the thickness of the wall tiles before grouting.
- Expansion joints not with grout – fill the joint between the wall and floor and corners with sanitary silicone, not cement grout.
Adhering large formats, waterproofing in the shower, and floor levelling should be left to an experienced tiler. If you are unsure about the substrate, consult a professional before purchasing materials.
Where to buy adhesive and grout
Adhesives, grouts, and silicones can be found on the e-shop vkupelni.sk in the category Sealants, adhesives and cleaning agents. We also have wall tiles, adhesives, and grouts in the studio, and we can help you choose the colour of the grout to match the wall tiles – see them live at the store in Senec at Bratislavská 71. You can calculate how much wall tiles and floor tiles to buy using the calculator How much wall tiles and floor tiles to buy.
Related: Adhesive, grout and trims · How much wall tiles to buy · Format 60 × 120 cm · All calculators
Sources: technical data sheet Ceresit CM 11 Plus (indicative consumption based on tile size and trowel teeth, bag 25 kg, combined method, processing time), technical data sheet Mapei Ultracolor Plus (formula for grout consumption, joints 2 to 20 mm, packaging 2 and 5 kg, joint preparation), technical data sheet Ceresit CE 40 Aquastatic (joints up to 8 mm, packaging 2 and 5 kg), technical data sheet JUB Akrinol Fugamix (formula for consumption with dimensions in cm), STN EN 12004 and STN EN 13888, e-shop vkupelni.sk (November 2026).
Terms in the glossary: Combined adhesive method · Trowel teeth · Porcelain stoneware (porcelain stoneware tiles) · Grout · Rectified tiles · Large-format tiles
Frequently Asked Questions
How much adhesive is needed for 1 m² of floor tiles?
Depending on the tile size, 2.0 to 4.8 kg per m². Ceresit CM 11 Plus states 2.0 kg/m² for tiles up to 10 cm, 2.7 kg for up to 15 cm, 3.4 kg for up to 25 cm, 4.2 kg for up to 30 cm, and 4.8 kg/m² for tiles over 30 cm.
How many bags of adhesive to buy for the bathroom?
For 20 m² of floor tiles 60 × 60 cm, 96 kg of adhesive is needed, which means 4 bags of 25 kg. With a 10% reserve for uneven substrate, 5 bags are needed. For large formats glued with a combined method, expect higher consumption.
How much grout is needed for 1 m²?
It depends on the format and joint. For floor tiles 60 × 60 cm and a 2 mm joint, approximately 0.1 kg/m²; for tiles 15 × 15 cm and a 3 mm joint, about 0.5 kg/m²; and for mosaic 10 × 10 cm, nearly 0.8 kg/m².
What is the depth of the joint?
The depth to which the grout joint is filled with grout. It usually corresponds to the thickness of the tile. Mapei states that joints should be empty before grouting to at least two-thirds of the thickness of the wall tiles.
Why is more adhesive needed for large formats?
A large tile requires a trowel with deeper notches and is applied using a combined method – adhesive is applied to both the substrate and the back of the tile to prevent voids underneath.
Does this calculation apply to other adhesives and grouts?
Roughly yes. Consumption varies slightly between products, and precise data can be found in the technical data sheet and on the packaging of the specific adhesive or grout.
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