Steel weight calculator
Mass of sheet, bar, tube, angle and channel from the dimensions — for the delivery note, the lifting plan and the quote.
How it is worked out
Cross-sectional area from the dimensions, multiplied by length and by density. The densities used are 7.85 g/cm³ for carbon steel, 7.9 g/cm³ for austenitic stainless, 2.70 for aluminium, 8.96 for copper, 8.5 for brass, 4.51 for titanium and 7.2 for cast iron.
Rolling tolerances mean the real piece is normally within a couple of per cent of the calculated figure. That is close enough for ordering and for a lifting check with a proper safety factor; it is not close enough to settle an invoice, which is what the weighbridge is for.
| Section | Cross-section formula |
|---|---|
| Plate, flat bar | F = a · b |
| Round bar | F = π/4 · d² |
| Square bar | F = a² |
| Round tube | F = π/4 · (D² − (D − 2t)²) |
| Box section | F = a·b − (a − 2t)·(b − 2t) |
| Angle | F = (a + b − t) · t |
Before you lift it
A 6-metre length of 100×100×10 angle looks manageable and weighs about 90 kg. Half of the accidents around fabrication happen with material that was underestimated by eye. Work the mass out first, then decide whether it is a two-person lift.
Densities
| Material | ρ, g/cm³ | Mass of 1 m² sheet, 1 mm thick |
|---|---|---|
| Structural steel | 7.85 | 7.85 kg |
| Stainless steel 304 / 316 | 7.90 | 7.90 kg |
| Cast iron | 7.20 | 7.20 kg |
| Copper | 8.96 | 8.96 kg |
| Brass | 8.50 | 8.50 kg |
| Titanium | 4.51 | 4.51 kg |
| Aluminium | 2.70 | 2.70 kg |
Steel calculators by section
This calculator does every shape, but when you already know what you came for it is quicker to open the page for that shape: it starts on it and carries a table of the common sizes.
| Calculator | What it works out |
|---|---|
| Steel beam weight | IPE 200 — 22.4 kg/m, IPE 300 — 42.2, HEB 200 — 61.3, HEA 300 — 88.3. Full EN 10365 and DIN 1025-1 tables and a calculator for length and quantity. |
| Steel channel weight | UPN 120 — 13.4 kg/m, UPN 160 — 18.8. Pick UPN or UPE, enter length and quantity: total mass from the DIN 1026 table, not a formula. Full size table. |
| Steel angle weight | L 50×50×5 — 3.77 kg/m, L 100×100×10 — 15.0. Every size to EN 10056-1 from 20×20×3 to 200×200×20, unequal legs included, with a calculator. |
| Tube and hollow section | Weight of round tube and hollow section from dimensions: diameter or sides plus wall thickness. Common commercial sizes to EN 10219 and the area formulas. |
| Sheet metal weight | Steel sheet 2 mm — 15.7 kg/m², 5 mm — 39.25, 10 mm — 78.5. Mass of a sheet, of a batch and of a square metre for steel, stainless and aluminium. |
Frequently asked questions
Which densities are used?
Steel 7.85, stainless 7.9, aluminium 2.70, copper 8.96, brass 8.5, titanium 4.51 and cast iron 7.2 g/cm³. That is close enough for rolled products; thin sheet runs one or two per cent out because of thickness tolerance.
Why does the figure differ from the delivery note?
Thickness tolerance. A sheet sold as 3 mm may sit a few tenths either side under EN 10051, and over a large area that is several per cent. The note gives the weighed mass, the calculator the nominal one.
What is mass per metre for?
For cutting lists and for bench arithmetic. Knowing that a 40×40×3 square tube runs about 3.4 kg/m lets you estimate frame weight and lifting in your head.
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