Concrete and Rebar Quantity Takeoff for Footings and Columns

Taking off concrete and steel is the basis for pricing the structure and ordering materials. The rule is simple: split the building into elements, calculate each with a geometric formula, then total by type. Accuracy comes from good organization, not complex formulas.

Concrete volume

• Isolated or strip footing: length × width × thickness (for strips, the total strip length).
• Column: cross-section area × height. A 0.40 × 0.40 column 3.0 m high = 0.48 m³.
• Beam: width × total depth × length, deducting the part shared with the slab as the agreed measurement method requires.
• Slab: area × thickness.

Example: ten isolated footings 2.0 × 2.0 m, 0.60 m thick: volume = 2.0 × 2.0 × 0.60 × 10 = 24 m³. Add a pouring waste allowance, usually 3% to 5% when ordering ready-mix, so the order is about 25 m³.

Reinforcement weight

Weight per metre of a bar of diameter d in millimetres: weight (kg/m) = d² ÷ 162 approximately. Common sizes:

A bar bending schedule multiplies number of pieces by length by weight per metre. Do not forget:

• Stirrup lengths including hooks and bends.
• Lap and anchorage lengths as the code requires.
• Concrete cover, which makes bars shorter than the element dimensions.
• Cutting waste, usually 3% to 5%.

A quick check by steel ratio

Divide steel weight by concrete volume for each element type. Every engineer knows roughly what slabs, beams and columns usually come to. If a ratio is far from normal, recheck the schedule. This check catches count and length errors before they reach the quotation.

Ready tools

Use the concrete quantity calculator for volumes and the rebar schedule and weight sheet for weights. Before pouring, work out excavation and backfill in the excavation and backfill sheet. Numbers here are illustrative, and structural design remains the designer’s responsibility.