Metal Weight Calculator — Rod, Tube & Bar

The calculator works in millimeters and meters. Pipe is where conversions go wrong: nominal pipe size (NPS) is a name, not a measurement. 1-1/2 in Schedule 40 pipe has a 1.900 in outside diameter and a 0.145 in wall, so you enter OD 48.26 mm and wall 3.68 mm. Entering 38.1 mm (1.5 in) undercounts the weight by about 23%.

Tube and bar are simpler because the name is the size: 2 × 2 × 1/8 square tube is 50.8 mm wide with a 3.175 mm wall. For gauge walls, look up the decimal in the Sheet metal gauge (16 ga = 0.065 in). US stick lengths convert as 20 ft = 6.096 m, 21 ft = 6.401 m and 24 ft = 7.315 m.

Calculator results for 1 ft lengths, with steel at 7,850 kg/m³ and aluminum at 2,700 kg/m³. The Schedule 40 figures match the published pipe tables (1.13, 1.68, 2.72 and 3.65 lb/ft) to within rounding.

Mental check: one square inch of steel section weighs 3.40 lb per foot.

Handrail order: 12 sticks of 1-1/2 in Sch 40 pipe × 21 ft, 8 sticks of 2 × 2 × 1/8 square tube × 24 ft, and 4 sticks of 1/4 × 2 flat bar × 20 ft, all mild steel.

• Pipe: OD 48.26 mm, wall 3.683 mm, length 6.401 m → 57.1 lb per stick, 685.6 lb for 12.
• Square tube: 50.8 mm, wall 3.175 mm, length 7.315 m → 76.6 lb per stick, 612.6 lb for 8.
• Flat bar: 50.8 × 6.35 mm, length 6.096 m → 34.0 lb per stick, 136.1 lb for 4.

Total: 650.6 kg = 1,434 lb. Many US service centers price steel per hundredweight (cwt = 100 lb), so this order is 14.34 cwt. Multiply by the quoted cwt price, then add cut charges and delivery.

Hot-dip galvanizing coats every surface the zinc can reach, including the inside of pipe and tube. Many galvanizers bill by weight. Estimate the added zinc as coated area × coating thickness × zinc density (7,135 kg/m³). An 85 µm coating (3.3 mils, ASTM A123 grade 85) weighs 0.606 kg/m², or 0.124 lb/ft².

Thin-wall sections gain the most as a percentage. Ask whether the bill uses black (uncoated) or shipped weight.

1. Entering the NPS as the OD. The error grows on small sizes.
2. Expecting the formula to match a tube catalog exactly. The calculator assumes sharp corners. Real tube has rounded corners, so published weights for square and rectangular tube usually run a few percent lower.
3. Comparing a per-stick price with a per-pound price without converting. Divide the stick price by the stick weight before you compare suppliers.
4. Leaving out drops. You pay for the full stick. Plan the cuts in the Linear cutting calculator and order whole sticks.
5. Treating all aluminum alloys as identical. The calculator's 2,700 kg/m³ suits 6061 and most extrusion alloys. Some high-strength grades are denser, so check the mill certificate for critical totals.

1. Take off every shape as size × length × count, in actual dimensions.
2. Run each line through the calculator, then add 3–5% for drops if you are not ordering whole sticks.
3. Convert the total to cwt for pricing and to pounds for freight.
4. Check handling equipment before delivery.

Forklift capacity is usually rated at a 24 in load center. A bundle of 24 ft sticks picked off-center pushes the center of gravity out and reduces the safe capacity. Lift long bundles at their balance point. On the truck side, US federal rules cap gross vehicle weight at 80,000 lb, so a heavy plate-and-beam order can reach the weight limit well before the deck is full. For full section tables, see Steel Weight Table: kg/m for Round Bar, Tube, Flat Bar and Pipe.