Concrete Volume Calculator

Calculate concrete volume in cubic metres for slabs, beams, footings or round columns, add a waste allowance and estimate the ready-mix cost from a price per cubic metre.

Rectangular: volume = length (m) × width (m) × thickness (cm) ÷ 100. Round column: volume = π × (diameter cm ÷ 200)² × height (m). Multiply by the number of pieces and by (1 + waste %) for the order quantity. Cost = order quantity × price per cubic metre ("kiew" in Thai).

Example: a 4 m × 3 m slab, 10 cm thick, is 1.2 cu m; with 5% waste order 1.26 cu m, about THB 2,520 at THB 2,000 per cu m. A round column 20 cm across and 1 m tall is π × 0.1² × 1 ≈ 0.0314 cu m.

A geometric volume estimate. Rebar is not deducted, and formwork, pumping, minimum delivery charges and concrete strength are excluded. Structural work should follow engineer-approved drawings, and confirm minimum loads with your supplier.