Calculate the weight of steel, stainless steel, aluminium or other metal plate, bar, pipe or tube — metric or imperial.
| Item | Value |
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Select your shape — plate/sheet, round bar/rod, square/rectangular bar, round pipe/tube, or square/rectangular tube — then choose a material from the standard density presets, or enter your own custom density. Enter the dimensions for your chosen shape and a quantity if you have more than one piece. Use the Cost tab with a price per kilogram or pound for a material cost estimate.
Steel weight is calculated by multiplying the material's volume by its density. Volume depends on the shape: for a flat plate it's thickness × width × length; for a round bar it's the cross-sectional circle area multiplied by length; for a pipe or tube, it's the outer cross-section minus the inner (hollow) cross-section, multiplied by length. Standard carbon steel has a density of approximately 7,850 kg per cubic metre (about 490 lb per cubic foot, or 0.284 lb per cubic inch) — this calculator uses that figure by default, with presets for other common metals.
Plate/Sheet: Volume = Thickness × Width × Length.
Round Bar/Rod: Volume = π × (Diameter ÷ 2)² × Length.
Square/Rectangular Bar: Volume = Width × Height × Length.
Round Pipe/Tube: Volume = π × [(Outside diameter ÷ 2)² − (Inside diameter ÷ 2)²] × Length, where inside diameter = outside diameter − (2 × wall thickness).
Square/Rectangular Tube: Volume = (Outside width × Outside height − Inside width × Inside height) × Length, where the inside dimensions are each reduced by twice the wall thickness.
Density varies by material, and to a lesser extent by specific alloy or grade. The values below are standard reference figures used throughout this calculator's material presets:
| Material | Density (kg/m³) | Density (lb/ft³) |
|---|---|---|
| Carbon / Mild Steel | 7,850 | 490 |
| Stainless Steel | 8,000 | 499 |
| Cast Iron | 7,200 | 450 |
| Aluminium | 2,700 | 169 |
| Titanium | 4,500 | 281 |
| Copper | 8,960 | 559 |
| Brass | 8,500 | 531 |
| Lead | 11,340 | 708 |
These are standard published reference values for general estimating. Grade and alloy variations (for example, different stainless steel grades, or leaded vs. unleaded brass) can shift a specific material's density by a small amount — for precision applications, use your supplier's certified figure.
The Cost tab multiplies your total calculated weight by a price per kilogram or pound that you enter. This is a material-only estimate — cutting, machining, surface finishing, delivery and supplier minimum order quantities aren't included. Metal prices fluctuate with commodity markets, so use your supplier's current quote for an accurate total.
Example 1 — Steel plate. A 10mm thick steel plate, 1000mm wide and 2000mm long: Volume = 0.010 × 1.000 × 2.000 = 0.02 m³. Weight = 0.02 × 7,850 = 157 kg.
Example 2 — Steel pipe. A steel pipe with 100mm outside diameter, 5mm wall thickness and 1000mm length: inside diameter = 100 − (2×5) = 90mm. Volume = π × (0.050² − 0.045²) × 1 = 0.001492 m³. Weight = 0.001492 × 7,850 ≈ 11.71 kg.
The most common mistake with pipes and tubes is using the outside diameter for the entire cross-section without subtracting the hollow centre, which significantly overestimates weight — a pipe's weight comes from the material in its wall, not the full solid cylinder. Another is mixing units, such as entering a diameter in millimetres but a length in metres without converting first (this calculator handles that automatically as long as you select the correct unit). For alloys and grades, using a generic steel density when working with a notably different material (like stainless steel, which is about 2% denser, or aluminium, which is roughly a third the density) will meaningfully skew results — always match the material preset to what you're actually calculating.
This calculator estimates a theoretical weight from the shape, dimensions and density you enter. It does not cover structural profiles with published mill section tables, such as I-beams, channels, or angle sections, since these require specific certified section data rather than a simple shape formula. Density presets are standard reference values for common materials and general grades — for a specific alloy, temper, or certified material, use your supplier's or mill's exact figure. This tool does not account for surface coatings, platings, or manufacturing tolerances, which can slightly change real-world weight.
Multiply the material's volume by its density. For a flat plate, volume is thickness × width × length; for a round bar, it's the cross-sectional circle area × length. Select your shape above, enter the dimensions, and the calculator does this automatically.
Standard carbon/mild steel has a density of approximately 7,850 kg per cubic metre (about 0.284 lb per cubic inch). Stainless steel is slightly denser at around 8,000 kg/m³. This calculator uses these standard reference values by default.
Multiply thickness × width × length to get volume, then multiply by steel's density (about 7,850 kg/m³). Select the Plate/Sheet shape above and enter your dimensions for an automatic result.
Subtract the inner cross-sectional area (based on inside diameter) from the outer cross-sectional area (based on outside diameter), multiply by length, then by density. Select the Round Pipe/Tube shape above and enter outside diameter, wall thickness and length.
For a round bar, weight equals π × (diameter/2)² × length × density. For a square or rectangular bar, it's width × height × length × density. Select the appropriate bar shape above and enter your dimensions.
Aluminium has a density of approximately 2,700 kg per cubic metre, roughly a third the density of steel. This is why aluminium components of the same size weigh significantly less than steel ones.
The same way as carbon steel - volume × density - but using stainless steel's density, which is slightly higher at around 8,000 kg/m³ compared to carbon steel's 7,850 kg/m³. Select Stainless Steel from the material dropdown above.
For a square or rectangular tube, subtract the inner (hollow) cross-sectional area from the outer cross-sectional area, multiply by length and density. Select the Square/Rectangular Tube shape above and enter outside dimensions, wall thickness and length.
Steel weighs approximately 490 lb per cubic foot, or about 0.284 lb per cubic inch, based on a density of 7,850 kg/m³. Multiply your material's volume in the matching unit by this figure for a quick weight estimate.
Density varies only slightly between most carbon and low-alloy steel grades (typically within 1-2%), so a standard 7,850 kg/m³ figure is accurate for most estimating purposes. Stainless steel and other alloys can have more noticeably different densities - use the correct material preset for your alloy.
I-beam and other structural profile weights depend on the specific section (like a W8x10 or UB), which this calculator doesn't include, since these require published mill section tables rather than a simple shape formula. Check the manufacturer's or mill's certified section properties table for an exact figure.