Metal weight.

Answer first. Weight = cross-section area x length x density. Steel is 7,850 kg/m3, so a 1 m long steel bar with a 1,000 mm2 section weighs 7.85 kg.

Worked example

A carbon steel plate 1,000 mm wide, 10 mm thick and 2,000 mm long: cross-section 1,000 x 10 = 10,000 mm2, volume 0.02 m3, weight = 0.02 x 7,850 kg/m3 = 157 kg (about 346 lb). A 1 in round steel bar 12 in long weighs 2.67 lb, or 2.67 lb per foot.

How it works

Formula. Section area: plate or flat bar = width x thickness; round = pi/4 x d2; square = side2; hex = (sqrt 3 / 2) x (across flats)2; round tube = pi/4 x (OD2 - ID2); rectangular tube = W x H - (W - 2t) x (H - 2t); angle = t x (A + B - t). Multiply by length for volume and by density for mass.

Densities used (kg/m3). Steel 7,850; stainless steel 8,000 (the source lists a range of 7,480 to 8,000, so this is the upper end and stainless weights may be a little lower); aluminum 2,712; copper 8,940; brass 60/40 8,520; phosphor bronze 8,900; titanium 4,500; zinc 7,135; lead 11,340. All are from the Engineering ToolBox density table. Specific alloys vary a little, for example 6061 aluminum is listed at 2,720.

Limits. Sections are drawn with sharp corners, so rolled angle, channel and tube with rounded corners weigh slightly different from the figure here. Always check the mill sheet or supplier's weight when you are paying by the pound or checking a load limit.

Safety. Heavy stock is a lifting and crushing hazard. Check the weight before you lift, use lifting aids and keep within the rated capacity of slings, racks and vehicles. This tool is an estimate, not engineering or load-rating advice.

Sources

• Metals and Alloys - Densities (Engineering ToolBox) (opened 2026-10-08)

Densities are from the page above. Unit conversions use 1 in = 25.4 mm and 1 lb = 0.45359237 kg.

FAQ

How much does a steel plate weigh?

Multiply width x thickness x length for the volume and then by 7,850 kg/m3. A 1 m x 1 m x 10 mm plate is 0.01 m3, or 78.5 kg.

How do I find the weight of a round bar?

Area = pi/4 x diameter squared, times length, times density. A 1 in steel round is about 2.67 lb per foot.

Which density does stainless steel use here?

8,000 kg/m3, the upper end of the 7,480 to 8,000 range in the source table. A given grade may be a little lighter.

Is aluminum weight the same for every alloy?

Close, not identical. The table lists aluminum at 2,712 kg/m3 and 6061 at 2,720. This tool uses 2,712.

Why does my supplier quote a different weight?

Rounded corners, mill tolerances and the exact alloy change the real weight. The supplier's figure is the one to rely on for pricing and loading.