A solid start for your next project
Self-levelling compound calculator
Estimate whole bags of ARDEX K 15 for an internal floor levelling job using the product maker's coverage guidance.
Your result
Your plan starts
with a few details.
Enter your floor area and average depth, then calculate to see the estimated whole bags.
How it works
Enter the floor area and the average compound depth required across that area. If the floor is uneven, measure a number of points and use a suitable average, this calculator does not determine the required depth or diagnose the cause of unevenness.
The estimate uses ARDEX K 15, a sourced 22 kg product example. Enter a waste allowance only if it reflects your surface and working conditions. The number of bags is rounded up to whole bags.
The September 2025 ARDEX data sheet specifies a 1.5–35 mm application range, it says the compound self-levels above 1.5 mm and a steel finishing float can be used for feather-edge touch-ups. The calculator therefore accepts average depths from 1.5 mm. Aggregate is required from 10 mm upwards and is not estimated. Follow current product instructions for priming, mixing, layer limits and substrate preparation.
Formula
Compound mass = area × average depth × 1.4 kg per m² per mm, with your entered extra allowance.
Bags to buy = compound mass ÷ 22 kg per bag, rounded up to a whole bag.
Worked example
For 10 m² at an average 3 mm, the ARDEX K 15 rate gives 10 × 3 × 1.4 = 42 kg. Divide by 22 kg per bag: 1.91 bags, rounded up to 2 bags.
This is a material estimate for the named product only. The supplier describes coverage as approximate, roughness, porosity, mixing and application conditions can change actual use.
Assumptions and limits
The calculator uses the stated coverage for ARDEX K 15, not a universal compound rate. The September 2025 ARDEX data sheet states 1.4 kg/m² per mm, a 1.5–35 mm application range, and aggregate from 10 mm upwards. Follow the current packaging and technical sheet for priming, application depth, compatible substrates and safe handling.
No primer, aggregate, edge sealing, levelling gauge, repair mortar or floor covering is included. The tool does not check moisture, substrate strength, movement joints, underfloor heating setup, floor coverings or whether a self-levelling product is suitable for your job.
This is a product quantity estimate, not installation or structural advice. Prepare the substrate and use protective equipment as specified by the maker. Ask the manufacturer or a qualified flooring professional if the surface, moisture condition or depth is outside the cited guidance.
Frequently asked questions
How many bags do I need?
Multiply area by average depth and the cited ARDEX K 15 usage rate, then divide by the 22 kg bag size and round up. Actual coverage varies with the substrate and application.
What depth should I enter?
Enter the average depth specified by your project or flooring professional. The calculator does not determine floor levels or prescribe a depth.
Does this include primer or aggregate?
No. Primer and any aggregate needed for thicker applications are not included in the bag estimate. The maker says aggregate is required from 10 mm upwards.
Can I use the result for any compound?
No. The result is based on the named product example and its published bag size and coverage. Other products have different rates and allowed depths.
Sources
- ARDEX K 15 Product Data Sheet, September 2025Checked on
- ARDEX K 15 product guidanceChecked on
Specs as of: