Tile adhesive calculator
Tile adhesive consumption depends mainly on the trowel: the deeper the notches, the thicker the bed of adhesive under each tile. Larger tiles need a bigger notch, and with it more adhesive per square metre.
Choose the notch depth and the calculator fills in a consumption value, which you can replace with the figure from the bag's data sheet. The result is rounded up to whole bags.
Your measurements
Filled in from the notch size; replace it with the figure from the bag's data sheet.
Result
- Adhesive needed
- 40 kg
- Bags to buy
- 2 pcs
Large tiles laid with back-buttering (adhesive on the floor and on the tile) use noticeably more adhesive.
How the calculation works
- Consumption (kg/m²) is taken from the notch depth: 3 kg/m² for 6 mm, 4 kg/m² for 8 mm, 5 kg/m² for 10 mm and 6 kg/m² for 12 mm — or the value you enter.
- Adhesive needed = area × consumption.
- Bags = adhesive needed ÷ bag size, rounded up.
Worked example
For 10 m² of tiles laid with an 8 mm notch trowel: 10 × 4 = 40 kg of adhesive, which is 2 bags of 25 kg.
What the calculator assumes
- The default consumption figures are deliberately on the safe side; manufacturers' data sheets often give a lower value for combed adhesive alone, so check the bag.
- A 6 mm notch suits small wall tiles, 8 mm standard floor tiles, and 10–12 mm large formats or slightly uneven floors.
- The calculation is for cement-based powder adhesive mixed with water.
When to adjust the result
- Large tiles laid with back-buttering (adhesive spread on both the floor and the back of the tile) use noticeably more adhesive.
- Adhesive does not level a floor: if the substrate is badly uneven, level it first with screed or a levelling compound.
- Outdoors, on underfloor heating or on wooden substrates, use a flexible (deformable) adhesive suitable for that use.
Frequently asked questions
How much tile adhesive do I need per square metre?
Typically between 2.5 and 6 kg/m², depending on the trowel notch and the tile size. Small wall tiles need the least; large floor tiles with back-buttering the most. The bag's data sheet gives the figure for that product.
Which trowel size should I use?
As a rule, the larger the tile, the deeper the notch. Lift a freshly laid tile now and then: the back should be almost fully covered with adhesive.
Can I use leftover adhesive later?
Mixed adhesive must be used within its pot life, usually a few hours. Unopened bags keep for months if stored dry; check the date on the bag.