Guide per m²
Tiles: order the floor area plus 5 to 15% cutting waste, depending on the layout pattern.
Tile adhesive: allow 1.5 to 3.5 kg per m², depending on the trowel notch (4 to 10 mm).
Grout: ((L + W) / (L × W)) × joint width × joint depth × density; for 60x60 with a 2 mm joint that is about 0.10 kg per m².
Open the tile calculatorThe number of tiles per m² is 1 divided by the area of one tile in m². A 60x60 cm tile is 0.36 m², so you need 2.78 tiles per m² for the surface itself. Cutting waste comes on top of that.
| Size (cm) | m² per tile | Tiles per m² |
|---|---|---|
| 15x15 | 0.0225 | 44.44 |
| 20x20 | 0.04 | 25.00 |
| 30x30 | 0.09 | 11.11 |
| 30x60 | 0.18 | 5.56 |
| 60x60 | 0.36 | 2.78 |
| 60x120 | 0.72 | 1.39 |
| 80x80 | 0.64 | 1.56 |
| 90x90 | 0.81 | 1.23 |
| 100x100 | 1 | 1.00 |
| 120x120 | 1.44 | 0.69 |
Some material is always lost at edges, around pipes and at doorways. How much depends on the layout pattern and the shape of the room. These are the percentages we use in practice at Il Mondo Tiles:
| Layout pattern | Cutting waste |
|---|---|
| Straight lay | 5 to 10% |
| Brick bond or staggered joints | 10% |
| Diagonal or herringbone | 15% |
A simple rectangular room is fine with the lower end of the range (5%). In a small room, or one with many corners or niches, use the upper end (10%). With 10% waste, 2.78 tiles per m² in 60x60 becomes about 3.06 tiles per m² to order.
Tip: order the extra tiles from the same production batch so colour and exact size match. Keep 1 box for later repairs: tiles ordered later can come out in a slightly different shade or size.
Want an exact count per box? Use the tile calculator on every product.
Adhesive consumption depends mainly on the trowel notch, the size of the teeth on the trowel. The figures on this page come from the technical data sheet of Coeck Tegellijm Flex Premium (version 04-2026, art. 281756), summarised in our own words.
Source: Coeck, premixed mortars
| Trowel notch (tooth size) | Consumption (kg per m²) |
|---|---|
| 4 mm | 1.5–1.7 |
| 6 mm | 1.9–2.2 |
| 8 mm | 2.5–2.9 |
| 10 mm | 3.2–3.5 |
Buttering-floating (adhesive on the tile as well) needs more adhesive than these table values.
This is an Il Mondo Tiles rule of thumb and does not come from the technical data sheet. 30x60 has a rule of its own: 8 mm notch, and buttering-floating only with brick bond or staggered joints.
| Size (cm) | Trowel notch | Buttering-floating |
|---|---|---|
| 15x15, 20x20 | 4–6 mm | No |
| 30x30 | 6–8 mm | No |
| 30x60 | 8 mm | Only with brick bond or staggered joints |
| 60x60 | 8–10 mm | Yes |
| 60x120, 80x80, 90x90, 100x100, 120x120 | 10 mm | Yes |
Buttering-floating needs more adhesive than the table value for the notch, so we add 1 extra bag below.
Area (m²) × consumption (kg per m², upper end of the range) ÷ 25 kg, rounded up. With buttering-floating, add 1 extra bag as a safety margin.
Example: 30 m² with a 10 mm notch: 30 × 3.5 = 105 kg, which is 4.2 bags, so 5 bags. With buttering-floating that becomes 6 bags.
A bag weighs 25 kg. You mix it with about 8 litres of water and get about 16 litres of adhesive mortar. A pallet holds 48 bags. One bag covers about 7 m² (10 mm notch) to 15 m² (4 mm notch).
| What | Value |
|---|---|
| Working temperature | 5 to 35 °C |
| Maturing time after mixing | 5 minutes |
| Pot life of the mixed adhesive | about 2 hours |
| Open time on the substrate | about 30 minutes |
| Adjusting tiles | within 15 minutes |
| Walkable and ready for grouting | after 24 hours |
| Full load | after 14 days |
Finger test for open time: touch the adhesive. If a skin has formed, the open time is over and you apply fresh adhesive.
The substrate must be firm, dry, load-bearing, crack-free and free of dust and grease. For thin-bed fixing, its moisture content must not exceed:
| Substrate | Max. moisture (CM-%) |
|---|---|
| Cement-bound substrate | 2.0 |
| Calcium sulphate | 0.5 |
| Heated anhydrite screed | 0.3 |
| Gypsum plaster | 1.0 |
Absorbent substrates (cement screed, plasterboard, aerated concrete): prime first. Non-absorbent substrates (concrete, levelling compound, tile on tile, and a stable, firmly fixed wooden board): use a bonding primer. Not sure whether a wooden substrate is stable enough? Ask for advice before you start.
Buttering-floating, also called back-buttering, means applying adhesive to the substrate and to the back of the tile. That fills the gap between tile and substrate completely, even with large tiles that are not perfectly flat.
We recommend it from 60x60 and for brick-bond layouts. If you comb the adhesive on both sides, draw the ridges in the same direction.
Product card
Class C2 TE S1 according to NBN EN 12004-1
Add the adhesive to your quote together with the tiles.
How much grout you need depends on the tile size, the joint width and the tile thickness. Small tiles have more joints per m² and therefore need more grout.
Grout (kg per m²) = ((length + width) ÷ (length × width)) × joint width × joint depth × density
We use a density of 1.6 kg per dm³. That is an indicative value: the exact value is on the technical data sheet of the grout you choose.
Example 60x60, 2 mm joint, 9 mm thick: (1200 ÷ 360000) × 2 × 9 × 1.6 = 0.096 kg per m², so about 0.10 kg per m².
| Size in cm (thickness) | 2 mm joint | 3 mm joint | 5 mm joint |
|---|---|---|---|
| 30x30 (8 mm) | 0.17 | 0.26 | 0.43 |
| 60x60 (9 mm) | 0.10 | 0.14 | 0.24 |
| 60x120 (9 mm) | 0.07 | 0.11 | 0.18 |
| 120x120 (10 mm) | 0.05 | 0.08 | 0.13 |
Add a small margin for losses while grouting and cleaning.
A 60x60 cm terrace tile that is 2 cm thick has the same area as an indoor tile: 2.78 tiles per m².
If you lay the tiles on pedestals, you need 1 pedestal at every point where four tiles meet. For 60x60 that is about 3 pedestals per m², plus extra pedestals along the edges. Allow for cutting waste on a terrace as well.
See our outdoor ranges: Series Liora, Series Nordio, All terrace tiles.
Thick outdoor tiles need outdoor clips: ILM-OCL-2.0 for 20–30 mm and ILM-OCL-3.0 for 30–40 mm. The numbers 2 and 3 mm in the name are the joint width, not the tile thickness.
You can find all clips, wedges and the selector on our levelling page.
A levelling system keeps large tiles flat and the joints even. How many clips you need depends on the tile size and on the clip. The table shows, for each IL-MONDO clip, the tile thickness it is suitable for and the number of clips per m².
| Clip | Joint width | Tile thickness | Up to 30x30 | Up to 60x60 | Up to 60x120 | Larger than 60x120 |
|---|---|---|---|---|---|---|
| ILM-CL-1.0 | 1 mm | 4–9 mm | 40–45 | 20–25 | 15–20 | 8–15 |
| ILM-CL-1.5 | 1.5 mm | 4–12 mm | 40–45 | 20–25 | 15–20 | 8–15 |
| ILM-CL-2.0 | 2 mm | 9–20 mm | 30–35 | 15–20 | 10–15 | 8–10 |
| ILM-CL-3.0 | 3 mm | 20–30 mm | 25–30 | 15–20 | 10–15 | 8–10 |
| ILM-OCL-2.0 | 2 mm | 20–30 mm | 30–35 | 15–20 | 10–15 | 8–10 |
| ILM-OCL-3.0 | 3 mm | 30–40 mm | 25–30 | 15–20 | 10–15 | 8–10 |
| ILM-SC-1.0 | 1 mm | 14–30 mm | 40–45 | 20–25 | 15–20 | 8–15 |
| ILM-SC-2.0 | 2 mm | 14–30 mm | 30–35 | 15–20 | 10–15 | 8–10 |
The columns follow the area of the tile: up to 0.09 m² (30x30), up to 0.36 m² (60x60) and up to 0.72 m² (60x120). Anything larger falls under 'Larger than 60x120'. Every tile side needs clips.
A bag of 250 clips costs €12.00 incl. VAT (€9.92 excl. VAT), by the bag in our showroom in Merelbeke.
You need wedges (ILM-WD-100) and spin caps (ILM-CP-100) for every clip that is in place at the same time. They are reusable 10 to 20 times.
A 30 m² living room with Limestone Ivory 60x60 (9 mm thick, 1.44 m² per box), laid straight, with a 2 mm joint. Every number comes from the formulas on this page.
| Item | Calculation | Result |
|---|---|---|
| Area with 10% cutting waste | 30 × 1.10 | 33.00 m² |
| Number of tiles | 33.00 ÷ 0.36 = 91.67 | 92 tiles |
| Boxes | 33.00 ÷ 1.44 = 22.92 | 23 boxes (33.12 m², 92 tiles) |
| Tile adhesive (10 mm notch, buttering-floating) | 30 × 3.5 = 105 kg ÷ 25 = 4.2 bags, rounded up to 5, plus 1 extra | 6 bags (150 kg) |
| Grout (2 mm joint, 9 mm thick) | 0.096 × 30 | 2.88 kg |
| Clips (ILM-CL-2.0, 2 mm joint) | 30 × 15–20 = 450–600 clips ÷ 250 = 1.8–2.4 bags, rounded up | 450–600 clips, 2–3 bags (€24–36 incl. VAT) |
| Wedges (ILM-WD-100) | 1 per clip in place at the same time | Reusable (10 to 20 times) |
Clips are calculated on the net area (30 m²), not on the 33.00 m² including cutting waste. You can read more about clips and wedges on the levelling page.
Allow 1.5 to 3.5 kg per m², depending on the trowel notch: 4 mm 1.5–1.7 kg, 6 mm 1.9–2.2 kg, 8 mm 2.5–2.9 kg, 10 mm 3.2–3.5 kg. A 25 kg bag therefore covers about 7 to 15 m². With buttering-floating you need more than the table value, so add 1 extra bag.
A 60x60 cm tile is 0.36 m², so 2.78 tiles per m². With 10% cutting waste, order about 3.06 tiles per m².
A 30x30 cm tile is 0.09 m², so 11.11 tiles per m². With 10% cutting waste, order about 12.22 tiles per m².
5 to 10% for a straight lay, 10% for brick bond or staggered joints and 15% for diagonal or herringbone. Order the extra from the same production batch and keep 1 box for later repairs.
Our rule of thumb: 15x15, 20x20 with 4–6 mm; 30x30 with 6–8 mm; 30x60 with 8 mm (buttering-floating only with brick bond or staggered joints); 60x60 with 8–10 mm and buttering-floating; 60x120, 80x80, 90x90, 100x100, 120x120 with 10 mm and buttering-floating. This is an Il Mondo Tiles guideline and does not come from the technical data sheet.
Calculate it with ((L + W) ÷ (L × W)) × joint width × joint depth × density, with dimensions in mm and an indicative density of 1.6 kg per dm³. For 60x60 with a 2 mm joint and 9 mm thickness that is about 0.10 kg per m²; for 30x30 with a 3 mm joint and 8 mm thickness about 0.26 kg per m².
With Coeck Tegellijm Flex Premium, the floor is walkable and ready for grouting after 24 hours and fully loadable after 14 days. You can adjust tiles within 15 minutes; the open time is about 30 minutes.
Buttering-floating, or back-buttering, means applying adhesive to the substrate and to the back of the tile. We recommend it from 60x60 and for brick-bond layouts, and we add 1 extra bag of adhesive for it.
Send us your m², the tile size and the layout pattern. You get a quote with a materials list: tiles, adhesive, grout and accessories.