Civil Engineering · Structural
Steel Weight Calculator
Weight of round bar, flat plate, or pipe from dimensions and density — for material takeoff and procurement.
Standard method — stated scope limits apply
Shape & Dimensions
Choose a shape and enter dimensions.
About This Calculation
Steel weight for a bar, plate, or pipe follows directly from its cross-sectional area, length, and the standard density of steel (7850 kg/m³) — the same calculation whether you’re estimating structural steel for a takeoff, checking a delivery note, or working out shipping weight. The geometry differs by shape (a solid circle for round bar, a rectangle for flat plate, an annulus for pipe), but the underlying physics — density × volume — is identical.
Frequently Asked Questions
What density value does this use, and does it vary by steel grade?
7850 kg/m³, the standard reference density for carbon and most structural/reinforcing steel grades — alloy content changes this only slightly for ordinary structural steels, not enough to matter for a material takeoff.
How is a pipe’s cross-sectional area calculated from outer diameter and wall thickness?
The pipe’s inner diameter is first found by subtracting twice the wall thickness from the outer diameter, then the area is the solid outer circle’s area minus the solid inner circle’s area — the same annulus (ring) geometry used for any hollow circular section.
Can I use this for a square or rectangular hollow section (box tube)?
Not directly — this covers round bar, flat plate, and round pipe. A rectangular hollow section would need the outer rectangle’s area minus the inner rectangle’s area, a straightforward extension not currently implemented as a separate shape option.
Is the weight this gives the same as what a mill certificate would show?
It should be very close — mill certificates use the same density-based calculation, though actual delivered weight can vary slightly from nominal dimensions due to rolling tolerances, which this calculator (using your entered nominal dimensions) doesn’t account for.