🔲 Metal Stock Weight

Written and maintained by the PhDino author · Last reviewed 21 September 2026 · Checked against 4 independent reference calculations · how PhDino checks its numbers

Estimating the weight of a length of round, square, flat, or tube metal stock.

Metal stock weight is simply cross-sectional area times length times material density — geometrically straightforward, but genuinely useful for shipping cost estimates, crane/lifting capacity checks, raw material ordering by weight instead of length, and sanity-checking a supplier's quoted weight.

Different common stock shapes just need their own cross-sectional area formula: a solid circle for round bar, a square for square bar, a rectangle for flat/plate, and a circle-minus-a-smaller-circle (an annulus) for round tube.

Key formula

Weight per foot = cross-sectional area (in²) × 12 (in/ft) × material density (lb/in³)
Total weight = weight per foot × length

Variables

ρ

material density, a fixed property of each metal (steel, aluminum, stainless, brass, …)

Notes & limitations

• These are nominal densities for common alloys — a specific alloy grade (many different steel or aluminum alloys exist, for instance) can vary slightly from the generic value used here, which matters more for a precise weight-based purchase than for a rough handling/shipping estimate.
• Tube wall thickness matters a lot to weight — a thin-wall tube of a given outer diameter can weigh a small fraction of the equivalent solid round bar, which is exactly why tube is chosen when strength-to-weight ratio (not raw stiffness) is the design driver.