Screed and floor levelling calculator (UK)
Work out how many bags of ARDEX screed or self levelling compound you need. Enter the area and the thickness, then add the bags to your basket.
How we calculate
Material needed (kg) = consumption (kg per m² per mm) × area (m²) × thickness (mm)
Bags needed = material needed ÷ pack size (kg), rounded up to a whole bag
The consumption figure for each product comes from ARDEX coverage data. If you choose a waste allowance of 5% or 10%, it is added to the material needed before the bags are counted. Example: 20 m² at 3 mm with ARDEX K15 (consumption 1.4 kg per m² per mm, 22 kg bag) needs 1.4 × 20 × 3 = 84 kg, which is 3.8 bags, so you need 4 bags.
Each product has its own minimum and maximum thickness. If your thickness is outside that range the calculator shows a warning and still gives you the result. Coverage values are approximate (manufacturer data). Check the product datasheet before ordering.
Frequently asked questions
How much screed do I need?
Multiply the area in m² by the thickness in mm and by the product consumption in kg per m² per mm. Divide by the bag size and round up. The calculator above does this for you.
How do I work out how much self levelling compound I need?
Use the same formula: area × thickness × consumption, divided by the bag size, rounded up. Pick a levelling compound in the calculator, enter the area and the depth you need, and it shows the number of bags.
How thick can I apply each product?
Every product has its own limits. The calculator warns you when the thickness you enter is outside the manufacturer range for the product you chose.
Should I allow for waste?
The calculator defaults to no waste allowance. You can add 5% or 10% for spillage and uneven floors, and the extra is included in the bag count.
Does this calculator cover sand and cement screed?
No. It covers selected ARDEX levelling compounds and screeds. Other brands and traditional sand and cement mixes are not included.
