How to Calculate Concrete for a Slab (Formula + Examples)
Calculate concrete for any slab: Volume = Length × Width × Thickness ÷ 27. Worked examples, a thickness guide, waste allowance, and bags-vs-ready-mix.
Concrete Slab
Guides, formulas, and tutorials for calculating concrete slabs — volume, cost, thickness, rebar, weight, and more.
How Much Does Concrete Weigh? Density Reference Guide (pcf, lb/yd³, kg/m³)
Normal concrete weighs 150 lb/ft³ (4,050 lb/yd³ or 2,400 kg/m³). Full density tables by concrete type, worked weight examples by volume, wheelbarrow capacity, and Cemex mix data — all in one reference.
How Much Concrete for a 10×10 Slab? (Bags, Yards & Worked Example)
A 10×10 slab needs about 1.23 cubic yards of concrete at 4 inches thick — roughly 56 × 80 lb bags, or order 1.35 yd³ ready-mix with waste. See the thickness table, bag counts, cost, and a worked example.
Featured Tool
Need instant results? Use the Concrete Slab Calculator.