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Steel Weight Calculator

Steel plate, bar and tube — weight from dimensions

Unit weight of steel7850 kg/m³7.85 g/cm³ · plate, bar, tube in kg or lb

What do you want to calculate?

Typical shop value for S275 / A36 class carbon steel.

Load a shop example

Weight

0.785kg

Volume
100 cm³
Volume (m³)
0.0001
Density
7.85 g/cm³
Density
7,850 kg/m³

V = L × W × T W = V × ρ

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Why a dedicated steel page?

Use this page when a supplier quote, nest, or cutting list is in steel and you need kilograms or pounds before you order. It is also the right starting point for flame-cut plate, turned bar, metal tube weight and welded pipework in carbon steel. For kg per metre of round bar or tube, enter diameter (and wall) and set length to 1 m.

Formula

Weight (kg) = Volume (m³) × 7850. For plate: L × W × T (in metres) × 7850. For round bar: π/4 × D² × L × 7850. Steel weight per metre is the same formula with L = 1 m.

10 mm steel plate, 2 m × 1 m

Volume = 2 × 1 × 0.010 = 0.020 m³. Weight = 0.020 × 7850 = 157 kg. Ø20 mm round bar weighs π/4 × 0.020² × 7850 ≈ 2.47 kg per metre.

Alloys on this page

  • Mild Steel — 7.85 g/cm³. Typical shop value for S275 / A36 class carbon steel.
  • Carbon Steel — 7.85 g/cm³. General carbon steels; similar mass to mild steel for estimating.
  • EN8 — 7.85 g/cm³. 080M40 medium-carbon steel, common for shafts and pins.
  • EN19 — 7.85 g/cm³. 709M40 alloy steel used for high-tensile shafts and gears.
  • EN24 — 7.85 g/cm³. 817M40 nickel-chromium-molybdenum steel.

Mill tolerances, mill scale and coatings add a little mass. Laser-cut parts lose the kerf. Tube and pipe use OD and wall — a metal tube weight calculator is the same hollow-cylinder formula. Unit mass of steel is 7850 kg/m³; weight of steel per cubic cm is 7.85 g and per cubic inch about 0.283 lb. It is also a mild steel weight calculator and a steel plate weight calculator (L × W × T × 7850). Worked examples: 20 mm steel plate 1 m × 1 m = 157 kg; Ø20 round bar ≈ 2.47 kg/m; 100 × 50 × 10 mm plate ≈ 0.39 kg; Ø50 × 3 mm tube ≈ 3.48 kg/m. If you need a certified shipping weight, weigh the bundle — this calculator is for engineering estimates and material take-offs.

How toolrooms estimate this before machining

Before we order plate or bar for a die, we run the blank size through this same formula. 7.85 g/cm³ is close enough for mild steel, EN8 and EN24 take-offs; stainless is heavier and we do not use 7.85 for it.

See the full material weight calculator for plastics, titanium, tool steels and custom densities, or jump to Aluminium, Copper, Stainless steel, Brass, Titanium.

Need mass from a CAD solid instead of typed sizes? Open the STEP, STP, IGES & IGS weight calculator. That page also weighs a SolidWorks part, a .3ds mesh, and a Rhino file. To view the model first and check a length, diameter, radius or angle, use the CAD Viewer.

Frequently asked questions

Is this a metal weight calculator and a steel weight calculator?+

Yes. It is a metal weight calculator for steel, stainless, aluminium, copper, brass and other shop metals, and a material weight calculator when you type dimensions. Dedicated pages cover a steel weight calculator, stainless steel weight calculator, copper and brass. Switch to STEP model to weigh a CAD solid.

How is metal weight calculated?+

Weight equals volume × density. Volume comes from the shape (for example length × width × thickness for a plate, or πr²L for a round bar). Density is looked up for the selected material, or entered manually for a custom alloy.

What density is used for mild steel?+

Mild steel is calculated at 7.85 g/cm³ (7850 kg/m³), which is the value most fabrication shops and steel stockholders use for estimating plate, bar and section mass.

Can I mix millimetres and inches?+

Yes. Each dimension has its own unit (mm, cm, m, inch, feet). The calculator converts everything internally to a consistent system before applying the density, then reports weight in the unit you choose.

How accurate is the result?+

The geometry is exact for the dimensions you enter. Real parts vary with mill tolerance, coating, chamfers and actual alloy density (stainless 304 vs 316, cast vs wrought aluminium). Treat the figure as a reliable estimate, not a certified weighbridge reading.

Does this include pipe schedules?+

Use the Pipe or Tube shape and enter outside diameter and wall thickness. That covers any schedule once you know OD and WT from a pipe chart. Tube and pipe use the same hollow-cylinder formula.

Which shapes can I calculate weight from?+

Plate and sheet (including sheet metal), round bar, square bar, rectangular bar, tube, pipe, solid cylinder, disc, and a custom box. That covers bar, part and component weight from dimensions as well as a metal mass take-off.

Which materials have densities built in?+

Mild steel, carbon steel, EN8, EN19, EN24, D2, H13, stainless 304 and 316, aluminium 6061 and 7075, copper, brass, bronze, titanium and cast iron. Plastics from the shop chart: PP, HDPE, ABS, PVC, PMMA, polycarbonate, PC+ABS, PC-PBT, nylon 6 and 66 (including glass-filled), PA46, POM / Delrin and TPE / TPU. Enter a custom density for anything else.

What is the unit weight of steel in kg/m³?+

The unit weight of steel used here is 7850 kg/m³ (7.85 g/cm³). That is also the unit weight of mild steel. Weight of steel per cubic cm is 7.85 g; per cubic inch about 0.283 lb. Stainless is 8000 kg/m³ — do not use 7850 for 304/316.

Can I calculate weight of material in kg?+

Yes. This is an online material weight calculator and metal weight calculator in kg (switch to lb, g, oz or tonne). Calculate weight of material from plate, bar, tube or a STEP solid. Carbon steel uses the same 7.85 g/cm³ as mild steel.

How much does a 20 mm steel plate weigh? What about round bar and tube?+

A 20 mm mild steel plate 1 m × 1 m weighs 157 kg (0.020 m³ × 7850). Ø20 steel round bar is about 2.47 kg per metre. A 100 × 50 × 10 mm plate is 0.39 kg. Steel tube Ø50 × 3 mm wall is about 3.48 kg per metre. Load those rows in the calculator.

Is this a steel plate weight calculator and a steel tube weight calculator?+

Yes. Steel plate weights are L × W × T × 7850 kg/m³. Round bar uses π/4 × D² × L × 7850. Tube and pipe use OD, wall and length (hollow cylinder). The steel weight calculator page locks 7850; stainless uses 8000 kg/m³.

Can I weigh a STEP or STP file?+

Yes. The dedicated weight calculator opens a .STEP, .STP, .IGES or .IGS solid in your browser and multiplies volume by density. Hide other components when you want the weight of one part. You can also switch to the CAD-file mode on this page. Treat the mass as a quotation estimate, not a certified scale reading.

How accurate is the weight from a STEP file?+

Volume comes from the closed solid, then multiplied by density. Fine fillets can change the last few percent. Confirm certified shipping weights on a scale.

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