Metal Weight Calculator
Metal weight = cross-sectional area × length × density. A 1 in round carbon-steel bar has 0.785 in² of section, so it weighs about 2.67 lb per foot — 53.5 lb for a 20 ft length. Aluminium of the same size weighs about a third as much. For plate by area, use the Plate Weight Calculator.
How it's calculated: Weight = section area (π(d/2)², side², or width × thickness) × length × density × quantity.
Result appears here
Fill in the fields and press Calculate.
Formula, calculation, assumptions and sources
Weight = cross-sectional area × length × metal density × quantity
Round area = π(d/2)² Square = s² Flat/sheet = width × thickness
Run the calculation to see each step with your own numbers.
A 1 in round carbon-steel bar, 20 ft long.
Area = π × (0.5 in)² = 0.785 in²
Weight per foot = 0.785 in² × 12 in × 0.284 lb/in³ = 2.67 lb/ft
Total = 2.67 × 20 = 53.5 lb
- Solid section (no radius at the corners of a square/flat bar, no crown on a sheet).
- Nominal densities for the common alloy in each family — a specific grade can vary ~1%.
- Length and cross-section are as entered; mill tolerance is not applied.
- Why is my steel bar heavier than the aluminium one the same size?
- Steel is about 2.9× the density of aluminium (7,850 vs 2,700 kg/m³). Same shape, same size, ~2.9× the weight.
- Which density does it use?
- Nominal published figures for the common grade in each family — carbon steel 7,850, stainless around 7,950, aluminium 2,700, copper 8,960 kg/m³. A specific alloy can vary about one percent.
- Does it account for the radius on the corners of a bar?
- No — it treats a square or flat bar as a perfect rectangle. The small rounding on hot-rolled bar makes the real weight a fraction under this figure.
- How much does a 1 inch steel bar weigh per foot?
- About 2.67 lb per foot for 1 in round carbon-steel bar: π × 0.5² = 0.785 in², × 12 in × 0.284 lb/in³. A 20 ft length weighs about 53.5 lb.
- How much does steel weigh per cubic inch?
- About 0.284 lb per cubic inch for carbon steel (7,850 kg/m³). Stainless is slightly heavier at around 7,950 kg/m³, and aluminium is about 0.098 lb/in³ (2,700 kg/m³).
Densities
Metal densities from the ASM Metals Reference Book / Machinery's Handbook: carbon steel 7,850 · stainless ~7,950 · aluminium 2,700 · copper 8,960 · brass ~8,500 · cast iron ~7,200 kg/m³.
About the Metal Weight Calculator
The Metal Weight Calculator gives the weight of a solid metal bar — round, square or flat — or a sheet, from its dimensions, length, quantity and alloy. It multiplies the cross-sectional area by the length and the metal's density, and also reports weight per foot so you can check it against a mill table. For hollow pipe or tube, use the Pipe Weight Calculator.
What you enter
- Shape
- Diameter
- Side
- Width
- Thickness
- Width
- Thickness
- Length — For a sheet, this is the length; width is entered above.
- Quantity
- Metal
What you get back
- Total weight — the exact result of the calculation.
- Weight per foot — the exact result of the calculation.
The formula, a worked example, the assumptions behind it and the sources are shown in full below the calculator.
Related calculators
- Pipe Weight Calculator — Weight of a length of pipe from its size, wall thickness and material.
- Plate Weight Calculator — Weight of a metal plate from its dimensions, thickness and material.
- Rebar Calculator — Rebar quantity, spacing and lineal feet for a slab or footing grid.
Part of the Materials calculators.