Floor Levelling Calculator — Compound & Materials Estimator
Estimate how much levelling compound you need to level an uneven floor. Covers self-levelling, floor patch and deep fill products.
Measure at multiple points and take the average
Choose based on depth range
Adds 10% extra for uneven areas and mixing losses
10% recommended for most levelling work
Enter your supplier price for a cost estimate
How We Calculate This
Our floor levelling calculator estimates the amount of compound needed based on your floor area and the average depth of unevenness. Different products have different coverage rates and are designed for different depth ranges.
The formula
Bags needed = (Area × Average depth × Coverage rate) ÷ Bag size
For example, levelling 15 m² at an average 3mm depth with self-levelling compound (1.6 kg/m²/mm): 15 × 3 × 1.6 = 72 kg ÷ 25 = 3 bags (before wastage).
Coverage rates by product type
- Self-levelling compound: 1.6 kg/m²/mm — best for 2-5mm depth, flows to a level finish
- Floor patch/repair: 1.8 kg/m²/mm — for localised dips and repairs, 1-10mm
- Deep fill compound: 1.5 kg/m²/mm — for 5-50mm depth, often used before self-levelling
These rates are based on typical UK products from Setcrete, Mapei, Weber and Ardex ranges. Always check the manufacturer's data sheet for exact coverage rates. Primer is calculated at 1 litre per 5 m² (standard acrylic floor primer coverage).
Frequently Asked Questions
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Last updated: February 2026
All calculations are estimates. Verify with your supplier.