⚙️ Structural Steel

Steel Weight Calculator — Rebar Weight Formula d²÷162

Calculate steel bar weight per metre, per bar, and total tonnage for any diameter and quantity. Uses the standard engineering formula W = d²/162 × L.

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Steel Weight Calculator

Weight per Metre · Per Bar · Total Kg · Total Tonnes

Quick click to select diameter:

6 mm

0.222 kg/m

8 mm

0.395 kg/m

10 mm

0.617 kg/m

12 mm

0.888 kg/m

16 mm

1.578 kg/m

20 mm

2.469 kg/m

25 mm

3.858 kg/m

32 mm

6.313 kg/m

Bar Diameter (mm) Or click a size above

Length per Bar (m) Standard bar = 12 m (40 ft)

Number of Bars

Wastage & Laps (%) Laps + cutting waste: 5–8%

📊 Results

✅ Calculated

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kg/m

Weight per Metre

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Weight per Bar

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Total Weight

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tonnes

Total Tonnage

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Total Length

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PKR

Est. Cost

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Enter different bar sizes with their quantities:

Diameter (mm)

Length (m)

No. of Bars

Description

📊 Multi-Bar Results

✅ Calculated

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Grand Total

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tonnes

Total Tonnes

Calculate cutting length for bent bars (stirrups, links, hooks):

Bar Diameter (mm)

Bar Type

Length A (mm)

Length B (mm)

Number of Pieces

Cover (mm)

📊 Cutting Length Results

✅ Calculated

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Length per Bar

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Total Length

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Total Weight

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📐 Steel Weight Formula — d²÷162 Explained

The standard formula for calculating the weight of a steel reinforcement bar is derived from the density of steel and the cross-sectional area of a circular bar.

W (kg/m) = d² ÷ 162 Where: W = Weight of bar per metre length (kg/m) d = Diameter of bar in millimetres (mm) Derivation: Area of bar = π/4 × d² (mm²) Density of steel = 7850 kg/m³ = 7850 × 10⁻⁶ kg/mm³ Weight per mm = Area × density = (π/4 × d²) × 7850 × 10⁻⁶ Weight per m = Weight/mm × 1000 = π/4 × d² × 7850/1000 = 0.006165 × d² ≈ d² / 162.2 → simplified to d²/162 Total Weight = (d²/162) × Length(m) × No. of Bars × (1 + Waste%)

The 162 constant is a simplified version of 1000/(π/4 × 7850) = 162.2. This formula is used universally across Pakistan, India, Saudi Arabia, UAE, and throughout engineering worldwide.

📋 Standard Steel Bar Weights — All Diameters

This reference table gives the weight per metre for all standard rebar sizes used in Pakistan and Gulf construction. Memorise the key values: 12mm = 0.888 kg/m, 16mm = 1.578 kg/m, 20mm = 2.469 kg/m.

Diameter	d²/162 (kg/m)	Weight/12m bar	Common Use in Pakistan
6 mm	0.222 kg/m	2.67 kg	Stirrups, ties, light mesh
8 mm	0.395 kg/m	4.74 kg	Stirrups, slab distribution bars
10 mm	0.617 kg/m	7.40 kg	Slab bars (short spans), footing ties
12 mm	0.888 kg/m	10.67 kg	Slab main bars, beams (light)
16 mm	1.578 kg/m	18.94 kg	Beam main bars, column ties
20 mm	2.469 kg/m	29.63 kg	Beam main bars, column main bars
25 mm	3.858 kg/m	46.30 kg	Heavy beams, large columns, raft
32 mm	6.313 kg/m	75.76 kg	Large columns, heavy industrial
40 mm	9.877 kg/m	118.5 kg	Massive foundations, bridges

✂️ Cutting Length Formulas for Standard Shapes

These are the standard formulas used by bar benders and structural engineers to calculate the actual length of steel required after bending.

Shape	Formula	Notes
Rectangular Stirrup	2(A+B) − 8d + hook allowance	A, B = inner dimensions. Hook = 9d each end
Circular Stirrup	π × (D−2c) + hook allowance	D = column dia, c = cover. Hook = 9d each
Standard 90° Hook	Straight length + 9d	Per IS 456 / BS 8666
180° Semicircle Hook	Straight length + 12d	Per IS 456 / BS 8666
Cranked / Bent Bar	L + 0.42d per crank	45° crank length allowance = 0.42d
L-shaped / Corner Bar	Leg1 + Leg2 − 2d	Subtract 1d per 90° bend

💡 Quick rule: For every 90° bend, deduct 2d from total straight length. For every 45° bend, deduct 1d. This accounts for the elongation of the bar during bending.

🇵🇰 Steel Prices in Pakistan — 2025 Market Rates

Reinforcement steel (rebar/sariya) prices in Pakistan fluctuate based on global steel prices, import duties, and local demand. These are approximate rates as of early 2025.

Brand / Type	Price per Tonne	Price per 40ft Bar (12m)	Grade
Amreli Steel (12mm)	PKR 2,20,000–2,40,000	PKR 195–213 (12mm)	Grade 60 / Fe500
Mughal Steel	PKR 2,15,000–2,35,000	PKR 191–209 (12mm)	Grade 60 / Fe500
Ittefaq Steel	PKR 2,10,000–2,30,000	PKR 186–204 (12mm)	Grade 60
AF Steel	PKR 2,00,000–2,20,000	PKR 178–195 (12mm)	Grade 40/60
Local / Foundry Steel	PKR 1,80,000–2,00,000	Lower quality	Grade 40 (approx)

⚠️ Always buy Grade 60 (Fe500) or Grade 40 (Fe415) steel from certified manufacturers for structural work. Local foundry steel has unknown strength and should only be used for non-structural purposes.

How to Check Steel Quality on Site

Check for manufacturer's rolling mark on the bar (brand name + grade embossed)
Weigh a sample bar — should match d²/162 per metre within ±5%
Bend test: bend 12mm bar 180° — should not crack on the outer radius
Request Mill Test Certificate (MTC) from supplier for large orders

❓ Frequently Asked Questions

Weight = d²/162 × L = (12×12)/162 × 12 = 144/162 × 12 = 0.888 × 12 = 10.67 kg per bar. A bundle of 10 bars = 106.7 kg. This is one of the most important values to memorise — 12mm bars are the most commonly used size in residential construction in Pakistan.

1 tonne = 1000 kg. Weight per 12mm bar (12m length) = 10.67 kg. Number of bars = 1000 ÷ 10.67 = 93.7 bars ≈ 94 bars per tonne. For ordering: specify "1 tonne of 12mm sariya" and expect approximately 94 bars of 12 metre length. Always ask for the actual count from the supplier for verification.

Per IS 456 and standard Pakistan practice: Minimum steel in a slab = 0.12% of cross-sectional area for Fe415/Fe500. For a 125mm thick slab: Ast(min) = 0.12/100 × 1000 × 125 = 150 mm²/m width. This equals approximately 10mm bars @ 520mm c/c or 8mm bars @ 330mm c/c. In practice, Pakistani residential slabs typically use 10mm or 12mm bars @ 150–200mm spacing.

Grade 40 (Fe415): Yield strength = 415 MPa (60,000 psi) — used for light residential work. Grade 60 (Fe500): Yield strength = 500 MPa (72,500 psi) — used for structural RCC in buildings, bridges, and commercial construction. Grade 60 is stronger but costs slightly more. In Pakistan, both Amreli and Mughal produce Grade 60 steel marked as "G-60" or "Fe500" on the bar rolling marks.

Steel Weight Calculator — Rebar Weight Formula d²÷162