Tile Adhesive Calculator UK
Work out how many bags of tile adhesive you need from the surface you are actually tiling and the coverage stated for your chosen adhesive and application. Extra allowance starts at 0%.
Calculate tile adhesive bags
Use a known tiled area, or enter simple surface dimensions. For irregular floors or multiple wall sections, total the area first with the Floor Area Calculator or Wall Area Calculator.
How the tile adhesive calculation works
The base estimate uses the coverage stated for the actual adhesive and application. Extra allowance is applied only when you choose it, then the final purchase quantity rounds up to whole bags.
Worked example
20 m² at 5 m² per bag = 4 theoretical bags.
At 0% extra that remains 4 bags. At 10% extra the planned area becomes 22 m², which is 4.4 theoretical bags and therefore 5 whole bags to buy.
Why coverage per bag is not a universal number
Coverage changes with the adhesive formulation and the way it is applied. Current manufacturer data illustrates the spread: ARDEX X 7 lists approximately 5.1 m² at 3 mm thickness per 20 kg bag, ARDEX X 7 R lists about 4.7 m² at 3 mm per 20 kg bag, and ARDEX X 77 advertises up to 8 m² per 20 kg bag. Mapei Keraflex publishes consumption as 2–5 kg/m² rather than one fixed area per bag. That is why this calculator asks for the figure that matches your product instead of inserting a generic default.
Calculate the floor or wall area that will actually receive adhesive. Keep separate areas separate if the adhesive or application method changes.
Use the manufacturer’s coverage or consumption figure for the exact adhesive, bag size and intended application. Do not substitute a generic internet rate.
The tool starts at 0%. If site conditions or your own planning approach justify extra material, enter the percentage yourself.
Trowel size and bed thickness affect use — but this tool does not choose them
Manufacturers publish application guidance for their products. The calculator does not decide the correct adhesive, trowel, bed thickness, substrate preparation or fixing method. Those are specification and installation decisions; this page only converts a measured area and a verified product coverage into a bag quantity.
Tile adhesive vs tile and grout quantity
This page owns adhesive bag quantity from tiled area and verified product coverage. Use the Tile Calculator for tile and box count, and the Grout Calculator for grout quantity. Keeping those jobs separate prevents one set of assumptions from contaminating another.
Should I add an extra percentage?
There is no hidden allowance here. Product coverage is approximate and site conditions can affect consumption, but one percentage is not correct for every job. Start at 0% and add only the extra quantity you deliberately want to plan for after checking the substrate, application method and product instructions.
Planning estimate only. Confirm the selected adhesive is suitable for the tile, substrate, location and installation system. Use the current manufacturer technical data and follow its preparation/application instructions before purchasing or fixing tiles.
Current manufacturer coverage examples
- ARDEX X 7 — approximately 5.1 m² at 3 mm per 20 kg bag.
- ARDEX X 7 R — approximately 4.7 m² at 3 mm per 20 kg bag.
- ARDEX X 77 — manufacturer states up to 8 m² per 20 kg bag.
- Mapei Keraflex — manufacturer states consumption of 2–5 kg/m².
Frequently asked questions
How much tile adhesive do I need per m²?
There is no single reliable rate for every adhesive and installation. Use the coverage or consumption published for the exact product and application you have chosen.
Can I use the same coverage for walls and floors?
Only if the manufacturer’s data and your specified application support it. If the product, substrate or application differs, calculate those areas separately using the relevant coverage figure.
Why does the calculator round up?
Adhesive is purchased in whole bags. A theoretical result of 4.1 bags therefore requires five bags unless your supplier sells a different unit.