Steel and Metal Weight Calculator
Mass, kg per metre and total batch weight for plates, bars, tubes, beams and angles.
Estimate the weight of steel plate, round bar, pipe, rectangular hollow section (RHS), I-beam, equal angle and hex bar in seconds. Choose mild steel, stainless steel, aluminium, cast iron, brass, copper, titanium or plastics, or enter your own density.
- Live results
- Full step-by-step working
- PASS / FAIL checks
- Free PDF report
Results
Step-by-step calculation (6 steps)
- 1Cross-sectional areaFormulaA = B·HSolutionA = 50 × 20ResultA = 1000 mm²
- 2VolumeFormulaV = A·LSolutionV = 1000 × 1000 = 1000000 mm³ResultV = 0.001 m³
- 3Mass per pieceFormulam = ρ·VSolutionm = 7850 × 0.001Resultm = 7.85 kg
- 4Mass per metreFormulam′ = ρ·A × 10⁻⁶Solutionm′ = 7850 × 1000 × 10⁻⁶Resultm′ = 7.85 kg/m
- 5Weight (force) per pieceFormulaW = m·gSolutionW = 7.85 × 9.81ResultW = 77.01 N
- 6Total mass for quantityFormulam_total = m·nSolutionm_total = 7.85 × 1Resultm_total = 7.85 kg
Engineering takeaways
- Rolled sections (I-beams, angles) have root radii that this model ignores; catalogue mass per metre can differ by about 2 to 5%.
- Add mill tolerance and cutting allowance (typically 3 to 10%) when ordering raw material.
The PDF report contains every input, formula, substitution and check shown above, in LTM calculation-sheet format.
Worked Example
Fabricators use this for raw material ordering and costing, and machine designers use it to estimate moving mass for motor and drive sizing. Every result shows the full working, so you can check it or attach it to a quotation.
The calculator above opens with this example. Change any input to run your own case.
Inputs
| Shape | Flat bar / plate |
|---|---|
| Material | Mild / carbon steel (7850 kg/m³) |
| Width / flange width B | 50 mm |
| Thickness / height H | 20 mm |
| Length L | 1000 mm |
| Quantity | 1 pcs |
Results
| Mass per piece | 7.85 kg |
|---|---|
| Mass per metre | 7.85 kg/m |
| Total mass (1 pcs) | 7.85 kg |
| Weight per piece | 77.01 N |
Steel Weight Formulas Used
Mass
- mmass (kg)
- ρdensity (kg/m³), 7850 for carbon steel
- Across-sectional area (m²)
- Llength (m)
Mass per metre
Round tube area
- Douter diameter
- twall thickness
Rectangular tube area
I-beam area (approx.)
- Bflange width
- tf, twflange and web thickness
Weight (force)
Basis: Geometry from nominal dimensions; densities from standard material data. Results are for preliminary design and should be confirmed against supplier data and the governing standard.
Steel Weight Calculator FAQ
How do I calculate the weight of a steel plate?
Multiply width × thickness × length in millimetres, then multiply by 7.85 × 10⁻⁶ kg/mm³. For a 1000 × 1000 × 10 mm mild steel plate: 10 000 000 mm³ × 7.85 × 10⁻⁶ = 78.5 kg. The calculator does this for any size and material.
What density should I use for mild steel and stainless steel?
Use 7850 kg/m³ for mild and carbon steel, 7930 kg/m³ for stainless 304 and about 8000 kg/m³ for 316. Aluminium 6061 is 2700 kg/m³, roughly one third of steel.
Why is my I-beam weight different from the IS 808 table?
Rolled sections have root radii at the web-flange junction and tapered flanges on some series. This calculator uses straight rectangles, so expect a 2 to 5% difference. Use the tabulated kg/m for purchasing and this result for quick estimates.
How do I convert kg per metre to total weight?
Multiply kg/m by the length in metres and by the number of pieces. The calculator shows mass per metre, mass per piece and total batch mass together.
Is weight the same as mass?
In everyday use weight means mass in kg. In engineering, weight is the force due to gravity, W = m × 9.81 in newtons. The calculator gives both, so you can use the force directly in beam or motor calculations.
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