By Zencalcy Editorial TeamLast reviewed About us
Steel takeoffs are always by mass, whether you are buying rebar, flat bar or a length of pipe. This calculator covers the shapes that dominate structural and workshop work, uses 7,850 kg/m³ for carbon steel, and reports both pounds and kilograms so a quote in either unit can be checked.
Weight of steel bars, plate and pipe for takeoffs and freight.
Plate: L × W × t × ρ Round: π × r² × L × ρ Square: s² × L × ρ Pipe: π/4 × (D² − d²) × L × ρ
Steel density is 7,850 kg/m³ (0.284 lb/in³). The classic estimating shortcut for round bar is weight per foot = 2.67 × diameter² (inches), which this calculator reproduces from first principles.
| Symbol | Meaning |
|---|---|
| ρ | 7,850 kg/m³ for carbon steel. |
| D, d | Outside and inside diameter of pipe. |
| L | Length of the piece. |
1 × 1 × 144 inches is 144 cu in, or 0.00236 m³. At 7,850 kg/m³ that is 18.5 kg, or 40.8 lb.
Continue with the Gravel Calculator, Sand Calculator, Rock Calculator, or the River Rock Calculator — or browse more materials & quantities and all construction calculators.
Number 4 bar is 0.668 lb/ft, number 5 is 1.043 lb/ft and number 6 is 1.502 lb/ft. Rebar size is eighths of an inch in diameter.
Results use standard construction estimating arithmetic: volumes from measured area and depth, unit weights from published material densities, and code-referenced spans or clearances where the page names a code. Quantities are rounded up to whole saleable units and include the stated waste allowance. These tools are planning aids, not structural design, and do not replace a licensed engineer, a local code check, or a contractor's site measurement.
Reference material used to build and check this calculator:
Last reviewed: September 2026. See how we build and check every tool on the about page.
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Content updated: September 2026