Column and Beam Concrete Calculator

How is column concrete calculated?

The concrete volume of a column is its section area times its height. For a rectangular column V = b × h × H, for a round column V = π / 4 × D² × H. Multiply by the number of identical columns to get the column concrete for a storey.

How is beam concrete calculated?

The top of a beam sits inside the slab. When the slab is measured separately, the slab thickness is deducted from the beam depth so that part is not counted twice: V = b × (h − t) × L. Use the clear span between column faces as the beam length.

Example

Twelve columns of 30 cm × 60 cm and 3 m high: 0.30 × 0.60 × 3 × 12 = 6.48 m³. With 5 percent waste the order is 6.80 m³.

Ten beams of 25 cm × 50 cm on a 12 cm slab with a clear length of 4.5 m: 0.25 × (0.50 − 0.12) × 4.5 × 10 = 4.275 m³.

Mind the joint

The volume where a beam meets a column is counted either with the column or with the beam, never with both. The usual way is to measure columns from top of slab to top of slab and beams between column faces.

Limits

The tool covers straight members with a constant section. Split haunched beams, corbels and walls into parts and calculate each one. It does not tell you whether the section sizes are adequate.