Steel Weight Calculator
Weight of steel plate, flat, round, square and hex bar, pipe, SHS, RHS, angle, channel and beam in kg and lb, per metre or foot, plus stainless and aluminium.
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About this toolWhat is the Steel Weight Calculator?
Steel is bought, shipped, lifted and often priced by weight, but it is specified by size. This steel weight calculator turns the size of a plate, bar, tube or rolled section into kilograms and pounds per metre, per foot, per piece and for the whole order. Enter the dimensions, the length and the number of pieces, and the total updates as you type.
Eleven shapes are covered: plate and sheet, flat bar, round bar, square bar, hex bar, round tube or pipe, square and rectangular hollow sections, angle, channel and I-beam. Hollow sections can use the corner radii from EN 10219 (cold-formed) or EN 10210 (hot-finished) instead of sharp corners, which brings the result within a percent of the published tables. The same size is also priced for stainless steel, cast iron, aluminium, copper, brass and titanium in a comparison table, and an optional price per kg or lb gives the material cost.
- Plate, flat, round, square and hex bar, round tube, SHS, RHS, angle, channel and I-beam
- EN 10219 and EN 10210 corner radii for hollow sections, or sharp corners
- Weight per metre and per foot, per piece and in total, in kg and lb
- Density presets for carbon and stainless steel, cast iron, aluminium, copper, brass and titanium, all editable
- Comparison table for every material, surface area for coating, optional cost
How to use the Steel Weight Calculator
- Choose metric (mm, m, kg) or imperial (in, ft, lb). Switching converts the sizes you already entered.
- Pick the shape and enter its dimensions. Tubes need the outside size and the wall thickness.
- For square or rectangular tube, choose cold-formed, hot-finished or sharp corners.
- Enter the length of each piece and the quantity, then pick the material or type a density.
- Read the total, the weight of each piece, the weight per metre or foot and the surface area; add a price per kg or lb for a cost.
Worked examples
Square hollow section 100 x 100 x 5 (default)
Input
Cold-formed SHS, 6 m length, carbon steel
Output
14.41 kg/m; 86.46 kg per 6 m length
The EN 10219 table lists 14.4 kg/m. With sharp corners the result would be 14.92 kg/m, about 3.5% heavy.
Steel plate
Input
2,000 x 1,000 x 10 mm plate
Output
157 kg (78.5 kg/m²)
Each millimetre of steel plate thickness weighs 7.85 kg per square metre, a handy number for quick checks.
Round bar for an order
Input
20 mm round bar, 6 m lengths, quantity 10
Output
2.466 kg/m; 14.8 kg each; 148 kg total
The total is what matters for a delivery or a hoist, and per metre is what suppliers quote.
Imperial plate and pipe
Input
1/4 in plate, 48 x 96 in; 2 in Schedule 40 pipe (2.375 x 0.154 in), 21 ft
Output
Plate 326.7 lb; pipe 3.657 lb/ft and 76.8 lb per length
ASME B36.10 lists 2 in Schedule 40 at 3.66 lb/ft, matching the calculation.
Background and insight
Weight is simply cross-section area times length times density. The area formulas are exact for the idealised shapes: a round tube is π(D − t)t, an angle is t(a + b − t), and a hollow section with rounded corners is 2t(B + H − 2t) − (4 − π)(ro² − ri²). The ASME B36.10 pipe weight formula, 10.69(D − t)t in lb/ft with inches, is the same equation with the steel density folded in.
Carbon steel is taken as 7,850 kg/m³ (0.2836 lb/in³), the value EN 10025 and most section tables use. Stainless grades are heavier: EN 10088-1 gives 7,900 kg/m³ for 1.4301 (304) and 8,000 kg/m³ for 1.4401 (316). Aluminium alloys are about 2,700 kg/m³, copper C11000 about 8,890 kg/m³ and cartridge brass about 8,530 kg/m³. All of these are typical values at room temperature; enter your supplier's figure if it differs.
Real stock is never exactly nominal. Mill tolerances on plate thickness and bar diameter (EN 10029, ASTM A6) allow a few percent either way, and rolled beams, channels and angles have root fillets that add a little area. Use the theoretical weight for estimating and quoting, and the certified weight on the delivery note for lifting plans.
Common use cases
Quoting fabrication jobs
Total the weight of plates, tubes and sections in a frame to price material and galvanising.
Lifting and transport
Check that a bundle of bar or a stack of plate is within a crane, forklift or trailer limit.
Comparing materials
See how much an aluminium or stainless version of the same part weighs before redesigning.
Estimating dead load
Get kg per metre of a beam or rail to add self-weight to a structural load calculation.
Tips and limitations
- Steel weight quick rules: plate is 7.85 kg/m² per mm of thickness, round bar is about 0.00617 d² kg/m with d in mm, and 1/4 in plate is 10.2 lb/ft².
- Galvanising adds roughly 3 to 7% to the weight of light sections, more on thin material.
- For rolled beams and channels with tapered flanges, use the published kg/m from the section table, which includes fillets; this tool assumes parallel flanges without fillets.
- Pipe is sold by nominal size, not outside diameter. A 2 in pipe has an OD of 2.375 in, so enter the actual OD and wall from the schedule table.
Frequently asked questions
How do you calculate the weight of steel?
Multiply the cross-section area by the length and by the density. In metric, area in m² times length in m times 7,850 kg/m³ gives kg. For a 1 m x 1 m x 10 mm plate that is 0.01 x 1 x 7,850 = 78.5 kg.
What is the density of steel in kg/m³ and lb/in³?
Carbon steel is 7,850 kg/m³, which is 0.2836 lb/in³ or 490 lb/ft³. Stainless 304 is about 7,900 kg/m³ and 316 about 8,000 kg/m³.
How much does a steel plate weigh per square metre?
7.85 kg per square metre for each millimetre of thickness. A 6 mm plate is 47.1 kg/m² and a 20 mm plate 157 kg/m². In US units, each inch of thickness is 40.8 lb/ft².
What is the formula for round bar weight per metre?
For steel, kg/m = 0.006165 x d², with d in millimetres. That comes from π/4 x d² x 7,850 / 10⁶. A 25 mm bar is 3.85 kg/m and a 16 mm bar 1.58 kg/m.
How do you calculate the weight of a steel pipe?
Use π x (OD − wall) x wall for the area. In US units with inches, steel pipe weighs 10.69 x (OD − t) x t lb/ft, the ASME B36.10 formula; in metric, 0.02466 x (OD − t) x t kg/m with millimetres.
Why does my calculated tube weight differ from the supplier table?
Hollow sections have rounded corners, which remove material. A 100 x 100 x 5 SHS is 14.9 kg/m with sharp corners, 14.7 kg/m hot-finished and 14.4 kg/m cold-formed. Choose the matching corner profile to get within about 1% of EN 10219 and EN 10210 tables.
Is aluminium really a third of the weight of steel?
Very nearly. Aluminium alloys are about 2,700 kg/m³ against 7,850 for steel, a ratio of 0.34. Aluminium is also only a third as stiff, so a part redesigned for the same deflection usually needs a larger section.
Is there an in-depth guide to the Steel Weight Calculator?
Yes. “Steel Weight Formulas for Plate, Bar, Pipe and Sections (kg/m and lb/ft)” covers the background, how it works, common pitfalls and worked examples. Read the full guide.
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