Metal Weight Calculator
Calculate the weight of metal stock for any common shape — round, square, flat and hex bar, round/square/rectangular tube and pipe, plate and angle — in steel, stainless, aluminum and other alloys. Enter the dimensions and length and get the weight in kilograms and pounds, per piece and for the whole quantity.
Weight calculator
Nominal weights from dimensions and density. Actual weight varies with mill tolerance, coating and alloy — confirm against the mill certificate for critical use.
Metal density reference
| Material | g/cm³ | kg/m³ | lb/in³ |
|---|---|---|---|
| Carbon steel | 7.85 | 7,850 | 0.284 |
| Stainless 304 | 7.93 | 7,930 | 0.287 |
| Stainless 316 | 8.00 | 8,000 | 0.289 |
| Stainless 430 | 7.70 | 7,700 | 0.278 |
| Tool steel | 7.80 | 7,800 | 0.282 |
| Cast iron | 7.20 | 7,200 | 0.260 |
| Aluminum | 2.70 | 2,700 | 0.098 |
| Copper | 8.96 | 8,960 | 0.324 |
| Brass | 8.50 | 8,500 | 0.307 |
| Bronze | 8.80 | 8,800 | 0.318 |
| Titanium | 4.51 | 4,510 | 0.163 |
| Nickel alloy | 8.40 | 8,400 | 0.303 |
| Zinc | 7.14 | 7,140 | 0.258 |
| Lead | 11.34 | 11,340 | 0.410 |
The formulas behind it
Every calculation is cross-sectional area × length × density. The area formula depends on the shape:
- Round bar: A = π/4 × d²
- Square bar: A = a² · Flat bar: A = w × t
- Hex bar: A = 0.866 × AF² (AF = across flats)
- Round tube: A = π/4 × (OD² − ID²), where ID = OD − 2t
- Square / rectangular tube: outer area minus inner area
- Angle: A ≈ (a + b − t) × t
Quick shortcut for steel round bar: kg/m = d² × 0.006165 (d in mm).
Frequently asked questions
How do you calculate the weight of steel?
Weight = cross-sectional area x length x density. For carbon steel the density is 7.85 g/cm3 (7,850 kg/m3). This calculator applies the correct area formula for each shape automatically.
What is the density of steel?
Carbon steel is 7.85 g/cm3. Stainless 304 is 7.93, stainless 316 is 8.00, aluminum is 2.70 and copper is 8.96 g/cm3.
How do I calculate round bar weight per metre?
For a round bar, weight in kg/m equals diameter in mm squared multiplied by 0.006165. A 20 mm bar is 20 x 20 x 0.006165 = 2.47 kg/m.
Does the calculator work for pipe and tube?
Yes. Enter outside diameter and wall thickness for round tube and pipe, or the outer dimensions plus wall thickness for square and rectangular tube. Only the wall material is counted.
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