Self-Leveling Concrete Calculator

Why This One Is Different

Set a 6-foot straightedge across your old slab and the gap underneath is rarely uniform, an eighth of an inch at one end, three-quarters at the other, and that unevenness is exactly what breaks flat-rate self-leveler estimates. A 50 lb bag covers roughly 46 to 48 square feet at a true 1/8" fill, but coverage scales inversely with depth: double your average fill to 1/4" and the same bag covers about half that area. This calculator asks for your measured average depth, not a guess, and flags that priming the substrate first is not optional.

Where the Numbers Come From

• LevelQuik RS covers 46-48 sq ft per 50 lb bag at a 1/8" reference depth; coverage scales inversely with average fill depth. Source: Custom Building Products, LevelQuik RS TDS-108 (rev. 2024-01-18)
• Real-world consumption is set by your measured average fill depth over an un-flat floor, which routinely doubles or triples bag counts versus the printed reference figure. Source: Custom Building Products LevelQuik RS TDS-108, via construction-estimating canon ("falsest-precision category")
• Priming a sound, primed substrate is a manufacturer requirement, not an optional step, before self-leveling underlayment is poured. Source: Custom Building Products, LevelQuik RS TDS-108
• A 300 sq ft floor at a measured 1/4" average fill needs roughly twice the bags of the same floor at 1/8", because coverage-per-bag halves as depth doubles. Source: worked example, closed-form geometry