Self-Levelling Compound Calculator — How Much Do I Need?

Work out how much self-levelling compound you need in seconds. Enter your floor area and the average depth you want to level, and we'll calculate the number of 20kg bags of Larsen SLC1550 required — including 10% for wastage.

How the Calculation Works

A 20kg bag of Larsen SLC1550 covers approximately 1m² at 10mm depth. The formula: bags = floor area (m²) × average depth (mm) ÷ 10, plus 10% for wastage and uneven spots. Example: a 20m² kitchen levelled at an average 5mm needs 20 × 5 ÷ 10 = 10 bags, so order 11.

Tips Before You Pour

Measure depth at several points and use the average — floors are rarely evenly out. Always prime the substrate first, and for timber floors use a flexible fibre-reinforced compound like SLC1550 or a two-part latex leveller. SLC1550 takes light foot traffic in 2–4 hours and can usually be tiled or overlaid after 1–3 days depending on depth and conditions.

Ready to Order?

Shop the full self-levelling compound range, grab a pallet deal for bigger jobs, or call our Coventry team on 0330 520 1804 for advice.