Self-Levelling Screed Consumption per m²: How Much You Need
Self-levelling compound consumption is about 1.7 kg per m² for every millimetre of thickness. Here is how to turn area and thickness into kilograms and 25 kg bags.
The basic formula
Required kg = area (m²) × thickness (mm) × 1.7. Bags of 25 kg = kg ÷ 25, rounded up. The value of 1.7 kg/m² per mm is typical for cementitious compounds, so always check the product data sheet.
Worked examples
20 m² at 5 mm: 1.7 × 5 = 8.5 kg/m²; 8.5 × 20 = 170 kg; 170 ÷ 25 = 6.8, so 7 bags (175 kg).
50 m² at 3 mm: 1.7 × 3 = 5.1 kg/m²; 5.1 × 50 = 255 kg; 255 ÷ 25 = 10.2, so 11 bags (275 kg).
Consumption by layer thickness
Bags are always rounded up to whole 25 kg bags.
| Thickness (mm) | kg per m² | 25 kg bags per 10 m² |
|---|---|---|
| 2 | 3.4 | 1.4 |
| 3 | 5.1 | 2.0 |
| 5 | 8.5 | 3.4 |
| 8 | 13.6 | 5.4 |
| 10 | 17.0 | 6.8 |
| 15 | 25.5 | 10.2 |
How to find the thickness
Check the unevenness with a long straightedge and a spirit level and use the average layer thickness, not the thinnest spot. Stay within the minimum and maximum thickness the manufacturer allows for one pour.
Add a reserve and prime first
Add 5–10 % for waste, an uneven substrate and the material left in the bucket, and apply the recommended primer first: it limits absorption and bubbles.
Common mistakes
- Using the thinnest point instead of the average thickness.
- Skipping the primer, which causes pinholes and uneven setting.
- Forgetting edge insulation tape along the walls.
- Pouring more than the maximum thickness in one layer.
- Buying exactly the calculated amount with no reserve.
Frequently asked questions
How many kg of self-levelling compound per m²?
About 1.7 kg per mm of thickness: 5.1 kg/m² at 3 mm and 8.5 kg/m² at 5 mm.
How many bags for 30 m² at 4 mm?
1.7 × 4 = 6.8 kg/m²; × 30 = 204 kg; 204 ÷ 25 = 8.2, so 9 bags of 25 kg.
Is the value the same for every product?
No. 1.7 kg/m² per mm is a common indicative value. The exact consumption is on the product's data sheet.
Open the calculator: Self-Leveling Compound