Steel Weight Calculator
A 12 mm round bar, 12 m long, weighs 10.65 kg at 7,850 kg/m³. That is 0.888 kg/m, 0.597 lb/ft, and 23.5 lb.
Last updated . Carbon steel starts at 7,850 kg/m³. The shape opens on that 12 mm bar. Other shapes load their own example when you select them.
Weigh a plate, flat, round bar, square bar, pipe, angle, channel, or I-beam from the dimensions you type. Length accepts meters, feet, centimeters, inches, and millimeters. The piece count starts at 1.
Reinforcing-bar sizes are on the rebar calculator. Mesh sheets are on the wire mesh calculator. Concrete volume is on the concrete calculator.
Steel weight
Results
How the weight is calculated
Weight is the cross-section area, in square meters, times the length, times the number of pieces, times the density. At 7,850 kg/m³ the 12 mm round bar is π ÷ 4 × 0.012² × 12 × 7,850 = 10.65 kg. The panel shows the area as 1.131 cm². Pounds per foot are kilograms per meter × 2.2046226218 ÷ 3.280839895. A short ton is 907.18474 kg.
| Shape | Area |
|---|---|
| Plate or flat | width × thickness |
| Round bar | π ÷ 4 × diameter² |
| Square bar | side² |
| Pipe | π ÷ 4 × (outside² − inside²). Inside = outside − 2 × wall. |
| Angle | (leg + leg − thickness) × thickness |
| Channel or I-beam | (depth − 2 × flange thickness) × web + 2 × flange width × flange thickness |
Channel and I-beam share that area expression because both are drawn here with two equal, parallel flanges. The channel flanges sit on one side of the web. The beam flanges sit on both sides. Neither shape looks up a catalog designation, and neither adds a fillet or a taper.
Worked example
Leave the shape on round bar, the diameter at 12 mm, the length at 12 m, the count at 1, and the density at 7,850. Area reads 1.131 cm². Weight per meter reads 0.888 kg/m. Weight per foot reads 0.597 lb/ft. Total weight reads 10.65 kg, 0.01 t, 23.5 lb, and 0.01 short tons. One bar of 12 mm rebar on the rebar page is the same 10.65 kg.
Switch the shape to plate. The loaded example is 2 m × 1,000 mm × 10 mm. Total weight reads 157.00 kg, 0.16 t, 346.1 lb, and 0.17 short tons. Weight per meter reads 78.500 kg/m.
Frequently asked questions
How much does a 12 mm steel bar weigh?
Leave the shape on round bar, the diameter at 12 mm, the length at 12 m, and the metal on carbon steel. The piece weighs 10.65 kg, 0.01 tonnes, 23.5 lb, and 0.01 short tons. That is 0.888 kg/m and 0.597 lb/ft, the same 12 mm figure as the rebar calculator. The area is 1.131 cm².
How do I weigh a steel plate?
Weight is width × thickness × length × density. Switch the shape to plate. The example is 2 m long, 1,000 mm wide, and 10 mm thick at 7,850 kg/m³, which is 0.020 m³ and 157.00 kg. That is 0.16 tonnes, 346.1 lb, and 0.17 short tons, or 78.500 kg/m.
How does the pipe weight work?
Pipe uses the outside diameter and the wall. Inside diameter is outside minus twice the wall. The example is 60 mm outside, 3 mm wall, and 6 m long, so the inside diameter is 54.0 mm. The area is 5.372 cm² and the pipe weighs 25.30 kg, 55.8 lb, at 7,850 kg/m³. A wall that is half the outside diameter or thicker is rejected.
How is angle iron weighed?
The area is (leg + leg − thickness) × thickness. That is the sharp-corner area. A rolled fillet is not added. The example is 50 mm × 50 mm × 5 mm, 6 m long: 4.750 cm² and 22.37 kg, 49.3 lb. Unequal legs use the same formula. Thickness has to be smaller than both legs.
How are channel and I-beam weights calculated?
Both use (depth − 2 × flange thickness) × web thickness + 2 × flange width × flange thickness. Flanges are equal and parallel. This is not a tapered mill beam and it does not look up a section designation. The channel example, 100 mm deep, 50 mm flange, 5 mm web, 6 mm flange thickness, 3 m long, is 24.49 kg. The I-beam example, 150 mm deep, 75 mm flange, 5 mm web, 8 mm flange thickness, 4 m long, is 58.72 kg and 129.5 lb.
Can I use this for aluminum or stainless steel?
Yes. The metal menu fills the density box, and the box is what gets multiplied. Stainless starts at 8,000 kg/m³, a planning figure, so the same 12 mm × 12 m bar is 10.86 kg instead of 10.65 kg. Aluminum starts at 2,700 kg/m³. The 2 m × 1 m × 10 mm plate is 54.00 kg in aluminum and 157.00 kg in carbon steel. Copper, brass, and cast iron are planning figures too. Type another density if the supplier quotes one.
Is 7,850 kg/m³ an assumption?
Not for carbon steel. It is the same density the rebar page uses for reinforcing bar. Square bar in the example is 20 mm × 6 m, 4.000 cm², 18.84 kg, and 41.5 lb. Flat bar in the example is 100 mm × 6 mm × 3 m, 14.13 kg. Stainless, aluminum, copper, brass, and cast iron on the menu are planning figures, labeled as such, and the density box stays editable.