Column Calculator

Calculate concrete volume, formwork area, and detailed steel reinforcement for rectangular columns. Export drawings to DXF.

Column Parameters

Width X (cm)

Depth Y (cm)

Height (m)

Clear Cover (cm)

Waste Factor (%)

Corner Reinforcement

Corner Bar Ø (mm)

Quantity (Usually 4)

X-Face Reinforcement (Top & Bottom)

X-Face Bar Ø (mm)

Qty per X-Face

Y-Face Reinforcement (Left & Right)

Y-Face Bar Ø (mm)

Qty per Y-Face

Stirrups / Ties

Stirrup Ø (mm)

Spacing (cm)

Cross Section

Elevation X-X

Elevation Y-Y

Material Estimate

Concrete Volume (m³)0.38

Formwork Area (m²)4.20

Total Steel Weight (kg)54.9

Mix (1:2:3 approx)

Cement (50kg bags)3

Sand (m³)0.19

Gravel (m³)0.29

Water (Liters)75

📝 Bar Bending Schedule (BBS)

Pos.	Element	Ø (mm)	Qty	Length (m)	Total (m)	Weight (kg)
01	Corner Reinforcement	16	4	3.60	14.40	22.76
02	X-Face Reinforcement (Top & Bottom)	12	2	3.60	7.20	6.40
03	Y-Face Reinforcement (Left & Right)	12	4	3.60	14.40	12.80
04	Stirrups / Ties	8	21	1.24	26.04	10.29

What is a Column Calculator?

This tool helps structural engineers and contractors estimate the exact concrete volume, formwork area, and steel reinforcement required for rectangular or square columns. It provides a detailed breakdown of corner bars, face bars, and stirrups.

How are the materials calculated?

Concrete volume is Width × Depth × Height. The formwork area is the perimeter of the column multiplied by its height. Steel is calculated by extracting the clear cover to determine the exact stirrup lengths and longitudinal bar heights.

Volume = W × D × H | Formwork = 2×(W + D) × H

Practical Example

For a column 30cm × 40cm and 3m high: Volume = 0.3 × 0.4 × 3 = 0.36m³. Formwork Area = 2 × (0.3 + 0.4) × 3 = 4.2m². If using 4 corner bars of 16mm and stirrups every 15cm, the calculator determines the exact rebar cut lengths and total weight.