Metal Weight Calculator
The weight of steel, stainless, aluminium, copper, brass or bronze plate, bar, tube or angle from its size, length and quantity, with the cost if you add a price.
Result…
How it's calculated
Weight = cross-section area × length × density × quantity Plate, flat bar: width × thickness Round bar: π × d² ÷ 4; square bar: side² Round tube: π ÷ 4 × (OD² − (OD − 2 × wall)²) Rectangular tube: W × H − (W − 2 × wall) × (H − 2 × wall) Angle: thickness × (leg A + leg B − thickness)
Works out the weight of metal stock from its cross-section, length and density: plate and sheet, flat, round and square bar, round tube or pipe, square or rectangular tube and equal or unequal angle. The densities listed come from published sources: 7850 kg/m³ for structural steel (Eurocode 3), 7.9 kg/dm³ for 304 stainless (Outokumpu), 2.70 g/cm³ for 6082 aluminium, 8.47 g/cm³ for CZ121 brass and 8.85 g/cm³ for CW451K phosphor bronze (Aalco datasheets), and 8940 kg/m³ for copper (Copper Development Association). Any other alloy can be entered by density. Sizes are in millimetres and metres or inches and feet, and the weight is shown in kilograms and pounds.
Your numbers, step by step
About the Metal Weight calculator
This metal weight calculator works out how much a piece of metal stock weighs from its shape, size, length and quantity. It covers plate and sheet, flat bar, round and square bar, round tube or pipe, square and rectangular tube and angle, in steel, 304 stainless, 6082 aluminium, copper, CZ121 brass and phosphor bronze, or any metal whose density you enter. It finds the cross-section area, multiplies by the length and density, and gives the weight per piece, per metre or foot and in total, in kilograms and pounds, with the cost if you add a price per kilogram or pound. Fabricators, buyers and engineers use it to plan lifting, transport and quotes. The densities come from Eurocode 3, Outokumpu, Aalco and the Copper Development Association, and the steps show every multiplication.
How to use it
- Choose metric (mm, m, kg) or imperial (in, ft, lb) units.
- Pick the “Shape” and the “Metal”, or “Enter the density” for another alloy.
- Enter the section sizes shown, such as the “Width”, “Height” and “Wall thickness” of a tube.
- Enter the “Length” of one piece and the “Quantity”.
- Add a “Price (optional)” per kg or lb to see the cost, then read the total weight.
Worked example
Eight lengths of 60 × 40 × 3 mm steel rectangular tube, 6 m long. Area = 60 × 40 − 54 × 34 = 564 mm². Weight per metre = 564 ÷ 1,000,000 × 7850 = 4.427 kg/m, so each 6 m piece weighs 26.564 kg and all eight weigh 212.515 kg (468.52 lb). At 1.1 per kg the steel costs 233.77.
Updated
Questions people ask
How do I calculate the weight of steel?
Multiply the cross-section area by the length to get the volume, then multiply by the density: 7850 kg/m³ for structural steel. In millimetres and metres, area (mm²) ÷ 1,000,000 × length (m) × 7850 gives kilograms.
What is the formula for the weight of a pipe or tube?
The wall's area is π ÷ 4 × (outside diameter² − inside diameter²), where the inside diameter is the outside diameter minus twice the wall. Multiply by the length and density for the weight.
How much lighter is aluminium than steel?
With densities of 2700 and 7850 kg/m³, the same size piece of aluminium weighs about 34% as much as steel. Exact figures depend on the alloy, so check the grade's datasheet.
Why doesn't my result match the supplier's table?
Rolled sections have rounded corners and size tolerances, and catalogue tables may use a slightly different density. The calculator gives the theoretical weight with sharp corners, which usually differs by a few per cent.
Can I use it for beams and channels?
Not directly: I-beams and channels have tapered flanges and root radii, so take their weight per metre or foot from the maker's section tables. For other solids, the density calculator relates mass, volume and density.
What are the limits of a metal weight estimate?
It ignores coatings such as galvanising, mill tolerances and corner radii. For lifting, transport limits or structural design, confirm the weights with your supplier or an engineer.