Steel Weight Calculator — Pipe, Plate, Bar and Tube
Enter the shape and the dimensions you measured and this calculator returns the weight per foot, the weight of one piece and the total for the whole order, in pounds and short tons. Steel is figured at 490 lb/ft³ (0.2836 lb/in³), the density AASHTO and FHWA use for structural steel; you can replace it with the figure on your mill certificate.
Weight of the order
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Results are estimates for planning purposes. Verify with your supplier, engineer, or a qualified professional before ordering material or performing work.
The four numbers behind every answer on this page
| What | Figure | Same thing, other units | Where it comes from |
|---|---|---|---|
| Carbon steel | 0.2836 lb/in³ | 490 lb/ft³ — 7,849 kg/m³ | FHWA NHI-04-041, citing AASHTO LRFD Table 3.5.1-1 |
| Aluminium | 0.0975 lb/in³ | 168.5 lb/ft³ — 2,699 kg/m³ | NIST elemental density 2.699 g/cm³ |
| Steel plate | 40.8 lb/ft² per inch of thickness | 0.2836 × 144 in² | Derived from the density above |
| Steel pipe or round tube | 10.69 × wall × (OD − wall) lb/ft | π × 12 × 0.2836 = 10.690 | Derived from the density above — not read off a schedule chart |
490 lb/ft³ is a convention for structural steel, not a measurement of your heat of material. Where a percent matters — a marginal pick, a truck at its axle limit — take the density from the mill certificate and put it in the density field.
Getting the dimensions right
Every answer here is only as good as the two or three numbers you measure. The three that go wrong most often:
- Outside diameter, not nominal size. A pipe called 6 in measures 6.625 in across the outside; a 2 in pipe measures 2.375 in. Tube, by contrast, is sold by its outside diameter. Measure it, or read it off the stencil.
- Actual wall, not schedule. Wall thickness is stencilled on the pipe and printed on the mill certificate. A wall-thickness gauge settles it on used material, which may have corroded well below its original wall.
- Hex bar is measured across the flats, the same dimension a wrench reads. Across the corners is about 15 % larger and gives a weight roughly a third too heavy.
Fractions are accepted in every field: type 3 1/2 or 0.375, whichever your tape gives you.
What this calculator does not do
- It has no pipe schedule chart. The tables that turn a nominal size and a schedule into an OD and a wall are ASME B36.10M and B36.19M — paid standards. Read your dimensions and type them in; the arithmetic does not care where they came from.
- It has no rolled-shape tables. W beams, channels, angles and tees have fillets and tapered flanges that no rectangle describes, and their published weights per foot are copyrighted. Take the weight per foot the producer prints for that shape and multiply by your length.
- It ignores corner radii on formed tube, so a square or rectangular tube comes out slightly heavy. On a long order, compare with the mill's published weight per foot.
- It does not add anything but the steel: no galvanizing, no coating, no water left in the pipe, no dunnage, no bands. On a truckload, those add up.
- It is not a load weight for a lift. 29 CFR 1926.1417(o)(3) wants the weight from a source or a calculation method recognized by the industry, given to the operator before the pick. Geometry qualifies — then add the rigging and check the tension in each leg with the sling tension calculator.
How it's calculated
- Cross-sectional area — plate, sheet or flat bar
A = width × thickness- Cross-sectional area — round bar
A = π / 4 × diameter²- Cross-sectional area — square bar
A = side²- Cross-sectional area — hex bar
A = (√3 / 2) × across-flats²A regular hexagon of width F across the flats has an area of 0.866025 × F². Measure across the flats, not across the corners.- Cross-sectional area — round pipe or tube
A = π / 4 × [OD² − (OD − 2 × wall)²] = π × wall × (OD − wall)- Cross-sectional area — square or rectangular tube
A = (W × H) − (W − 2 × wall) × (H − 2 × wall)Corner radii are ignored, so the result is slightly heavy for a formed tube. The mill's published weight per foot is the exact figure.- Weight per foot
lb/ft = A (in²) × 12 in × density (lb/in³)With carbon steel at 0.283565 lb/in³ this is A × 3.4028 lb/ft. Applied to a pipe it becomes 10.690 × wall × (OD − wall), the constant printed in pipe weight tables — recomputed here from the density, not copied from a chart.- Weight of the order
total = lb/ft × length (ft) × number of piecesA short ton is 2,000 lb. Mill tolerance on plate and pipe means the delivered weight is normally within a few percent of the calculated one, either way.- Density conversion
1 lb/ft³ = 1 / 1,728 lb/in³ ; 1 g/cm³ = 62.427960576 lb/ft³490 lb/ft³ ÷ 1,728 in³/ft³ = 0.283565 lb/in³, the figure usually rounded to 0.2836.
Frequently asked questions
0.2836 lb per cubic inch for carbon steel, which is the same thing as 490 lb per cubic foot — the density FHWA and AASHTO use for structural steel. One cubic foot of steel weighs about a quarter of a short ton.
Multiply the wall thickness by the outside diameter minus the wall thickness, then multiply by 10.69: lb/ft = 10.69 × wall × (OD − wall), with both dimensions in inches. That constant is nothing more than π × 12 × 0.2836, so it already contains the density of carbon steel. A pipe with a 6.625 in OD and a 0.280 in wall works out to about 18.99 lb/ft.
About 40.8 lb per square foot for every inch of thickness — 0.2836 lb/in³ × 144 in². So 1/2 in plate is roughly 20.4 lb/ft², 1/4 in plate about 10.2 lb/ft², and 1 in plate about 40.8 lb/ft².
Because the tables that turn a nominal pipe size and a schedule into an outside diameter and a wall thickness are published in ASME B36.10M and B36.19M, which are paid standards we do not reproduce. Read the dimensions off the stencil on the pipe, the mill certificate or your supplier's catalog and type them in — the arithmetic is the same either way, and it works for tube, which has no schedules at all.
Close, but not identical. Mills roll to a thickness tolerance and ship to a weight tolerance, so a plate order usually lands within a few percent of the theoretical figure. Use the calculated number for planning the lift, the truck and the rack; use the scale ticket for the invoice.
Aluminium is built in at 168.5 lb/ft³, the NIST elemental density. For stainless, tool steel, cast iron or a specific alloy, switch the material to "other alloy" and enter the density from the mill certificate or the producer's data sheet — austenitic stainless runs a little heavier than carbon steel, and the difference is worth carrying on a big order.
Rolled shapes have fillets and tapered flanges that a simple rectangle cannot describe, and their dimensions and weights are published in the AISC shape tables, which are copyrighted. Take the weight per foot printed for that shape by the producer and multiply by your length. This calculator covers the shapes you can measure with a tape and a caliper.
Yes. 29 CFR 1926.1417(o)(3) requires the weight of the load to be determined from a source or a calculation method recognized by the industry and given to the crane operator before the lift. Geometry and a published density are such a method, but add the rigging, the water inside the pipe and anything strapped to the bundle before you compare with a sling's rated capacity.
Sources & references
- FHWA NHI-04-041 — LRFD Design Example for Steel Girder Superstructure Bridge: structural steel 0.490 kcf (490 lb/ft³), citing AASHTO LRFD Table 3.5.1-1
- NIST — X-Ray Mass Attenuation Coefficients, Table 1: elemental density of aluminium, 2.699 g/cm³
- NIST Special Publication 811 — Guide for the Use of the International System of Units: 1 in = 25.4 mm and 1 lb = 0.45359237 kg, both exact
- 29 CFR 1926.1417(o)(3) — the weight of the load must be determined from a source or a calculation method recognized by the industry and given to the crane operator before the lift
Content checked against these sources — last reviewed September 1, 2026.