How much adhesive do I need per m²?
It depends on the tile size and the trowel: ~2 kg/m² for small tiles (4 mm trowel), 4 kg/m² for 30×30 cm (8 mm) and 5-7 kg/m² for floor/large format (10-12 mm). Back-buttering multiplies it by about 1.6.
Free tile adhesive and grout calculator: kg and bags per m² by tile size, trowel and joint width. For floor and wall, porcelain and ceramic.
Reference consumption for cement-based adhesive. Back-buttering (large tile/exterior) multiplies it by about 1.6:
| Tile size | Trowel | Adhesive |
|---|---|---|
| ≤ 10 × 10 cm | 4 mm | ~2 kg/m² |
| ≤ 20 × 20 cm | 6 mm | ~3 kg/m² |
| ≤ 30 × 30 cm | 8 mm | ~4 kg/m² |
| ≤ 60 × 60 cm | 10 mm | ~5 kg/m² |
| > 60 cm / floor | 12 mm | ~6–7 kg/m² |
kg/m² = ((A + B) / (A × B)) × joint width × thickness × 1.6 — with A, B, joint and thickness in mm. Small tiles and wide joints use more grout.
Still need the tiles? Use our tile & porcelain calculator (how many per m²).
Floor: 4 m × 3 m = 12 m², 30 × 30 cm tiles, 8 mm thick, 3 mm joints.
Adhesive: a 30 cm tile needs an 8 mm notched trowel, about 3.2 kg/m². Adding buttering and waste (~15%): 12 × 3.2 × 1.15 ≈ 44 kg, so 2 × 25 kg bags.
Grout: ((length + width) ÷ (length × width)) × joint width × tile thickness × 1.6. ((30+30)/(30×30)) × 0.3 × 0.8 × 1.6 ≈ 0.26 kg/m² → 12 × 0.26 ≈ 3.2 kg, one 5 kg bag covers it with margin for waste.
Adhesive class: standard cement (C1) suits small interior wall tiles; use flexible C2 for floors, large formats, porcelain, underfloor heating, and outdoors. S1/S2 add deformability for movement-prone substrates.
Trowel size drives consumption: 6 mm notch for mosaics, 8–10 mm for 30–60 cm tiles, 12 mm or a slope-bed for large slabs. Bigger notch = more kg/m².
Grout type: cement grout (CG2) for most joints; epoxy (RG) for wet rooms, pools, and where stain resistance matters. Match joint width to tile size — wider joints and rougher tiles eat noticeably more grout.
It depends on the tile size and the trowel: ~2 kg/m² for small tiles (4 mm trowel), 4 kg/m² for 30×30 cm (8 mm) and 5-7 kg/m² for floor/large format (10-12 mm). Back-buttering multiplies it by about 1.6.
Grout = ((A+B)/(A×B)) × joint width × thickness × 1.6, with measurements in mm. Small tiles and wide joints use more.
4 mm for mosaics, 6 mm up to 20 cm, 8 mm up to 30 cm, 10 mm up to 60 cm and 12 mm (with back-buttering) for large format and exterior.
Add the powder to clean water (follow the manufacturer ratio, about 0.25-0.30 L per kg), mix to a smooth lump-free paste, let it slake for 5 minutes and remix. Do not add more water afterwards. Spread it diagonally across the joints with a rubber float and wipe off the excess with a damp sponge before it sets.