How much steel is required for a 1000 sq ft slab?

For a 5 inch slab about 950–1,200 kg (80–100 kg per cum). The exact quantity comes from the structural drawing and BBS.

How to calculate the weight of a steel bar?

Weight in kg per metre = d²/162, where d is the diameter in mm. A 12 mm bar weighs about 0.889 kg/m.

How much steel for an RCC slab – kg per sq ft and per cum

Thumb rules for estimating reinforcement before the bar bending schedule (BBS). Final quantity always comes from the structural drawing.

bar weight (kg/m) = d² ÷ 162 (d in mm)

Thumb rules (approximate)

Element	kg steel per cum of concrete
Slab	80–100
Beams	120–160
Columns	160–220
Footings	60–80

For a whole residential RCC frame building, a common rough figure is 3.5–4.5 kg of steel per sq ft of built-up area.

Example: 1000 sq ft slab, 5 inch thick

1000 × 0.417 ft = 417 cft = 11.8 cum → 11.8 × 80–100 ≈ 950–1,200 kg of steel (Fe500 TMT).

Weight of TMT bars

Diameter	kg per m	kg per 12 m bar
8 mm	0.395	4.74
10 mm	0.617	7.40
12 mm	0.889	10.67
16 mm	1.58	18.96
20 mm	2.47	29.6

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AI Onin is a free AI assistant for construction: material quantities, BOQ, cost estimates and site photo analysis. Values are approximate (India, 2026); always follow your structural drawings, IS codes and the manufacturer's data. Structural design must be checked by a licensed structural engineer.