Enter the dimensions, pick a material, get the weight. Works in millimetres and kilograms or inches and pounds, for plate, round bar, pipe, square and rectangular tube, angle, hex bar and rebar. Every result shows the formula it came from, so you can check it before you order.
Weight calculator
Need saved projects, 30+ materials, standard section catalogues (IPE, HEA/HEB, UPN, UB/UC, angles), price per kg and PDF export?
Get it on iPhone & iPad →How the calculation works
Every metal weight calculation is the same three steps, whatever the shape:
- Cross-section area — the area of the profile when you cut it straight through, in mm².
- Volume — cross-section area × length.
- Weight — volume × density of the material.
Written as one line for metric units:
Weight (kg) = Cross-section area (mm²) × Length (m) × Density (kg/m³) ÷ 1 000 000
The only thing that changes between a round bar and a rectangular tube is how you work out the cross-section area. Here are the ones used on this page:
| Shape | Cross-section area (mm²) |
|---|---|
| Plate, sheet, flat bar | thickness × width |
| Round bar | π × d² / 4 |
| Square bar | a² |
| Hex bar (across flats) | 0.866 × a² |
| Pipe / round tube | π × (OD − wall) × wall |
| Square tube | 4 × (side − wall) × wall |
| Rectangular tube | 2 × (height + width − 2 × wall) × wall |
| Angle | (leg A + leg B − thickness) × thickness |
| Rebar | π × d² / 4 |
Tube and angle formulas assume sharp corners. Real hot-rolled sections have root radii, so a rolling-mill table will be 1–2 % heavier than the geometric result. For structural steel you should always order from the standard table, not from a geometric estimate — the app has IPE, IPN, HEA, HEB, HEM, HL, HD, HP, UB, UC, UPN, UPE, PFC and MS Angle catalogues built in.
Density of common metals
Density is the single number that turns volume into weight. Get the alloy wrong and the answer is wrong, no matter how carefully you measured.
| Material | Density (kg/m³) | Density (lb/in³) |
|---|---|---|
| Carbon / mild steel | 7,850 | 0.2836 |
| Stainless steel 304 | 8,000 | 0.289 |
| Stainless steel 316 | 8,000 | 0.289 |
| Stainless steel 430 | 7,700 | 0.278 |
| Aluminium 6061 | 2,700 | 0.0975 |
| Aluminium 5052 | 2,680 | 0.0968 |
| Copper | 8,960 | 0.324 |
| Brass C360 | 8,500 | 0.307 |
| Bronze | 8,800 | 0.318 |
| Cast iron | 7,200 | 0.260 |
| Titanium Grade 2 | 4,510 | 0.163 |
| Zinc | 7,140 | 0.258 |
| Nickel | 8,900 | 0.321 |
| Magnesium | 1,740 | 0.0629 |
| Lead | 11,340 | 0.410 |
Worked example
A 6 m length of 60 × 3 mm mild steel pipe.
- Cross-section area = π × (60 − 3) × 3 = 537.2 mm²
- Volume = 537.2 mm² × 6 m = 0.003223 m³
- Weight = 0.003223 × 7,850 = 25.3 kg
At 4.22 kg per metre, a bundle of twenty 6 m lengths comes to 506 kg — which is what decides whether it goes on the truck or needs a second trip.
Pick your shape
Each of these pages has a dedicated calculator, a reference table and worked examples:
FAQ
Is this calculator accurate enough to order material? For plate, bar, tube and rebar, yes — those are simple geometry and the result matches supplier tables. For hot-rolled structural sections (I-beams, channels, angles) use the published mill table instead, because the fillet radii add weight the geometric formula does not see.
What density should I use for steel? 7,850 kg/m³ (0.2836 lb/in³) for carbon and mild steel. Stainless is heavier at about 8,000 kg/m³. Using the mild steel figure for a stainless job under-estimates the weight by roughly 2 %.
How do I get weight per metre or per foot? Set the length to 1. The calculator also shows linear weight on every result, which is the number most suppliers price against.
Does it handle imperial units? Yes. Switch to Imperial and enter inches for the cross-section and feet for the length; the result comes back in pounds.
Can I calculate cost, not just weight? Not on this page. Price per kilogram or per pound, saved projects and PDF export are in the iOS app.
Do this on the jobsite instead
Steel Metal Weight Calculator for iPhone and iPad does everything on this page offline, plus the parts a web page cannot:
- 30+ materials and custom densities
- Standard section catalogues: IPE, IPN, HEA, HEB, HEM, HL, HD, HP, UB/UC, UPN/UPE, PFC, MS Angle, T-bars
- Rebar and grating calculators
- Save calculations into a project and copy the whole summary into an email or report
- Price per kg → cost of the order
- Export to PDF
- Reference tables: gauge, thickness, hardness-to-tensile, temper, melting points, fraction conversion
- 33 languages