Concrete quantity
calculator
Estimate how much ready-mix concrete you need for a slab, column, beam, or footing — with a recommended grade and a one-click quote from our Prakasam district plants near Ongole.
What this calculator is doing
The calculator multiplies the dimensions you enter to compute the volume of the element in cubic metres, then adds a wastage allowance — concrete is typically over-ordered by 5–10 % to cover spillage, formwork absorption, and uneven base levels. For multiple identical elements (a row of columns, several footings), multiply the per-unit volume by the count.
Common formulas
- Slab — length × width × thickness. A 4 m × 3 m slab cast 150 mm thick needs 4 × 3 × 0.15 = 1.80 m³ of concrete.
- Column — cross-section × height. A 230 mm × 230 mm column 3 m tall needs 0.23 × 0.23 × 3 = 0.16 m³.
- Beam — width × depth × length. A 230 mm wide × 450 mm deep beam spanning 5 m needs 0.23 × 0.45 × 5 = 0.52 m³.
- Footing — for an isolated footing, treat it as length × width × thickness like a slab. For a stepped footing, calculate each step separately and add the volumes.
Choosing a grade
- M15 / M20 for plain concrete, blinding, and lightly loaded RCC in non-aggressive exposure.
- M20 / M25 for standard residential RCC — slabs, beams, columns, footings in G+1 to G+3.
- M25 / M30 for commercial and mid-rise residential, longer spans, and moderate exposure.
- M30 / M35 for high-rise, severe coastal exposure, and bridge / industrial work — see our grade catalogue for the full spec sheet on each grade.
The grade recommendations in the calculator are defaults — your structural designer's drawings always take precedence. If you're unsure, call us and we'll talk through what other buyers in your area typically order for similar elements.