How this concrete calculator works
Slab-focused preset: start from length, width, and thickness to get an instant wet volume. Circular and triangular footprints use the same thickness dimension perpendicular to the slab plane.
How to calculate concrete volume
Multiply footprint area by thickness (height of the pour). For a rectangular slab, V = L × W × T. Circles use V = π × r² × T. Triangles use footprint area ½ × base × height times thickness.
What is a mix ratio?
Ratios like 1:2:4 describe relative volumes of cement : fine aggregate (sand) : coarse aggregate before water is added. Richer mixes (more cement) generally gain strength but cost more.
Material estimation notes
We expand wet volume to dry materials using a 1.54 bulk factor and your wastage percentage. Densities are typical defaults (cement ~1440 kg/m³). Always validate against local batch plant guidance.
Construction tips
- Order 5–10% extra for uneven subgrades and spillage — adjust the wastage slider accordingly.
- Coordinate pump or chute access before locking truck counts.
- Keep reinforcement clear cover consistent; spacing assumptions here are informational.