Calculate the exact weight of reinforcing steel bars (rebar) for your construction project with our professional-grade calculator. Whether you’re planning a residential foundation, commercial building, or infrastructure project, accurate rebar weight calculations are essential for material ordering, cost estimation, and structural integrity.
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Expert Tip: Always follow the relevant Australian Standards (AS3600, AS/NZS4671) and project-specific engineering requirements.
Understanding Rebar Weight Calculations
Reinforcing steel bars (rebar) are essential components in concrete construction, providing tensile strength to complement concrete’s compressive strength. Accurate weight calculations are crucial for:
- Material Ordering: Ensure you order the right amount of rebar to avoid costly overages or project delays from shortages
- Cost Estimation: Calculate precise material costs for accurate project budgeting
- Structural Design: Verify that the reinforcement meets engineering specifications
- Transportation Planning: Determine trucking requirements and load distribution
- Inventory Management: Track material usage and maintain optimal stock levels
Rebar Weight Specifications
| Bar Size | Nominal Diameter (mm) | Actual Diameter (mm) | Weight (kg/meter) |
|---|---|---|---|
| N10 | 10.0 | 11.5 | 0.650 |
| N12 | 12.0 | 13.8 | 0.930 |
| N16 | 16.0 | 18.4 | 1.660 |
| N20 | 20.0 | 23.0 | 2.590 |
| N24 | 24.0 | 27.6 | 3.710 |
| N28 | 28.0 | 32.2 | 5.050 |
| N32 | 32.0 | 36.8 | 6.600 |
| N36 | 36.0 | 41.4 | 8.350 |
| N40 | 40.0 | 46.0 | 10.310 |
Common Applications by Bar Size
Light Reinforcement (N10-N12)
- Residential slabs and driveways
- Small retaining walls
- Sidewalks and pathways
- Temperature and shrinkage control
Medium Reinforcement (N16-N24)
- Residential foundations and footings
- Columns in low-rise buildings
- Beams and floor slabs
- Swimming pools and water tanks
Heavy Reinforcement (N28-N40)
- High-rise building cores
- Bridge decks and piers
- Industrial foundations
- Heavy load-bearing structures
Important Considerations
When planning your rebar requirements, keep these factors in mind:
- Overlap Requirements: Bars must overlap at joints, typically 40-60 times the bar diameter
- Concrete Cover: Maintain proper concrete cover (typically 40-75mm) for corrosion protection
- Bar Spacing: Follow engineering specifications for minimum and maximum spacing
- Bending Allowance: Account for additional length when bars need to be bent
- Wastage Factor: Industry standard is 3-5% wastage for straight bars, 5-8% for bent bars
