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Calculate weight

Steel & Metal Weight Calculator

Calculate the weight of steel plate, round bar, tube and pipe from dimensions and density. Also covers aluminium, copper, brass, stainless and plastics.

Typical shop value for S275 / A36 class carbon steel.

Result

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

How the calculator works

Mass is volume multiplied by density. The calculator converts every dimension to millimetres, computes volume in cubic millimetres, then applies the material density (g/cm³) and reports kilograms, grams, pounds, ounces or tonnes.

Formula

W = V × ρ

ρ_steel = 7.85 g/cm³ = 7850 kg/m³

Plate: V = L × W × T

Round bar: V = π r² L

Tube: V = π L (Rₒ² − Rᵢ²)

Example — 10 mm mild steel plate, 2 m × 1 m

V = 2 × 1 × 0.010 = 0.020 m³
W = 0.020 × 7850 = 157 kg

Material densities used

Figures match common stockholder and workshop practice, not every mill certificate. Stainless 304/316 is 8.00 g/cm³, aluminium 6061 is 2.70, 7075 is 2.81, copper 8.96, brass 8.50. Enter a custom density when a drawing or cert specifies one.

Weight by metal

Need to convert the result into pounds or tonnes, or check a length in inches? Open the unit converter.

Frequently asked questions

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.

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