How much does the metal weigh?

How do I calculate the weight of steel?

Multiply the volume by the density. Steel weighs about 0.2836 pounds per cubic inch (490 lb per cubic foot). A plate ¼ inch thick, 12 inches wide and 48 inches long is 0.25 × 12 × 48 = 144 cubic inches, so it weighs 144 × 0.2836 = 40.8 pounds.

How much does steel weigh per foot?

It depends on the shape. A 1 inch round bar weighs 2.67 pounds per foot, 2 inch Schedule 40 pipe (2.375 inch outside, 0.154 inch wall) weighs 3.65 pounds per foot, and a 2 × 2 × ¼ inch angle 3.19 pounds per foot. The calculator shows the weight per foot of any size you enter.

How much lighter is aluminum than steel?

Aluminum is about a third of the weight: 2.70 grams per cubic centimeter against 7.85 for steel. The same ¼ × 12 × 48 inch plate weighs 14.0 pounds in aluminum and 40.8 in steel. The table under the result shows your piece in every metal.

Why is my supplier's weight a little different?

Real tubes and angles have rounded corners, and mills roll within a tolerance, so catalog weights differ slightly from a sharp-cornered calculation. Alloys also vary: stainless and brass grades differ by a few percent. For structural steel shapes, use the published weight per foot.

What are the densities of common metals?

In grams per cubic centimeter (and pounds per cubic foot): carbon steel 7.85 (490), stainless steel about 8.0 (499), aluminum 2.70 (169), copper 8.96 (559), brass about 8.5 (531), cast iron about 7.2 (449).

How much does a square foot of steel plate weigh?

About 40.8 pounds per square foot for each inch of thickness, so a ¼ inch plate is about 10.2 pounds per square foot. Aluminum is about 14 pounds per square foot per inch of thickness.

What size do I enter for a hex bar?

The distance across the flats, which is how hex bar is sold. The corners are farther apart (about 1.155 times the flats). A 1 inch hex bar has a section area of 0.866 square inches and weighs 2.95 pounds per foot in carbon steel, against 3.4 for a 1 inch square bar.

Which size do I enter for pipe?

The outside diameter and the wall thickness, not the nominal pipe size. A pipe sold as 2 inch (NPS 2) has an outside diameter of 2.375 inches; the wall depends on the schedule. Entering 2 inches as the outside diameter would understate the weight.

How the weight is calculated

Weight is the cross-section area times the length times the density. The calculator finds the area from the shape: width × thickness for plate, π × d² ÷ 4 for round bar, a² for square bar, (√3 ÷ 2) × a² for hex bar, π × (D² − d²) ÷ 4 for pipe, t × (a + b − t) for angle, and the outer rectangle minus the inner one for rectangular tube. It does not add rounded inside corners, fillets or mill tolerance, which is why published weights for structural shapes differ slightly. Density comes from the table of common metals, in grams per cubic centimeter, converted to pounds per cubic inch.

Worked example: a flat bar in three metals

A flat bar ½ inch thick, 3 inches wide and 10 feet (120 inches) long has a section of 3 × 0.5 = 1.5 square inches, so a volume of 180 cubic inches. In carbon steel (7.85 g/cm³) it weighs 51 pounds (23.2 kg). The same bar in aluminum (2.70 g/cm³) weighs 17.6 pounds (8 kg), and in stainless (8.0 g/cm³) 52 pounds (23.6 kg). The volume is identical; only the density changes the weight.

Common mistakes

Mixing units is the usual error: thickness in fractions of an inch, length in feet. Convert everything to inches before multiplying, or enter the length in the field provided and let the calculator convert. A second error is treating sheet gauge numbers as inches; gauge is a code that differs between steel, stainless and aluminum, so enter the actual thickness from the supplier. A third is using one density for all steels: stainless and carbon steel differ by about two percent, and alloys such as brass and bronze vary more, so the result is an estimate to a few percent, not a certified weight.

Sources: densities are typical handbook values (ASM International, MatWeb) as listed in the table of metals above; weights checked against 1 inch round bar (2.67 lb/ft), 2 inch Schedule 40 pipe (3.65 lb/ft) and 2 × 2 × ¼ inch angle (3.19 lb/ft). Related: material weight calculator, pipe volume calculator, concrete weight calculator.