Steel Weight Calculator
A steel weight calculator multiplies a shape's volume by steel density, 490 pounds per cubic foot. Pick plate, bar, pipe, tube, angle or a beam designation, enter the size and length, and read pounds, kilograms and tons. A half inch plate measuring 48 by 96 inches weighs 653.33 pounds.
This tool is part of our project calculators. It gives a theoretical weight from nominal size. It is not a lifting plan or a structural check.
- Updated November 2026
- Sources Cited
- No Login Required
- Free to Use
Your weight
Total weight
653.33 pounds
Weight uses 490 lb/ft3.
- Weight per foot
- 81.667 lb/ft
- One piece
- 653.33 lb
- Plate per square foot
- 20.42 lb/ft2
- Total pounds
- 653.33
- Total kilograms
- 296.35
- Short tons (2,000 lb)
- 0.3267
- Metric tonnes
- 0.2963
Theoretical weight from nominal size. Mills roll within tolerance. Not a lifting plan or a structural check.
Ten shapes
Plate, flat, round, square and hex bar, pipe, tube, angle and beams by name.
Four weight units
Pounds, kilograms, short tons and metric tonnes in one result.
Your density
Carbon steel, stainless steel or a custom value from 400 to 600 lb/ft3.
Weights are for estimating. Check the mill ticket before a lift or a haul. Pricing the steel? Try our construction cost calculator.
How to calculate steel weight
Multiply the volume of the piece by the density of steel. Steel weighs 490 pounds per cubic foot, or 0.2836 pounds per cubic inch. Find the volume in cubic inches from the size and length, then multiply by 0.2836. Divide by 2,000 for short tons.
- Pick the shape and read its size off the drawing or the order.
- Find the volume in cubic inches: area of the cross section times the length.
- Multiply by 0.2836 pounds per cubic inch to get pounds.
- Multiply by the number of pieces. Divide by 2,000 for short tons or multiply by 0.4536 for kilograms.
For rebar quantities, use our rebar calculator.
Steel weight formulas by shape
Each shape has its own volume formula. Plate is thickness times width times length. A round bar is 0.7854 times diameter squared times length. A pipe subtracts the inner circle from the outer circle. The tables list all ten, with pounds per foot for one example size.
Plate and flat bar
| Shape | Pounds per foot formula | Example size | lb per ft |
|---|---|---|---|
| Plate | Thickness x width x length x 490 / 1728 | 1/2 in x 12 in wide | 20.417 |
| Flat bar | Thickness x width x 12 x 490 / 1728 | 1/4 in x 2 in | 1.701 |
Round, square and hex bar
| Shape | Pounds per foot formula | Example size | lb per ft |
|---|---|---|---|
| Round bar | 0.7854 x diameter squared x 12 x 490 / 1728 | 1 in diameter | 2.673 |
| Square bar | Side squared x 12 x 490 / 1728 | 1 in side | 3.403 |
| Hex bar | 0.866 x across flats squared x 12 x 490 / 1728 | 1 in across flats | 2.947 |
Pipe and tube
| Shape | Pounds per foot formula | Example size | lb per ft |
|---|---|---|---|
| Round pipe or tube | 0.7854 x (OD squared - ID squared) x 12 x 490 / 1728 | 2.375 in OD, 0.154 in wall | 3.656 |
| Square tube | (Side squared - inner side squared) x 12 x 490 / 1728 | 4 in, 1/4 in wall | 12.760 |
| Rectangular tube | (a x b - inner a x inner b) x 12 x 490 / 1728 | 4 in x 6 in, 1/4 in wall | 16.163 |
Angle and shapes by designation
| Shape | Pounds per foot formula | Example size | lb per ft |
|---|---|---|---|
| Angle | Thickness x (leg 1 + leg 2 - thickness) x 12 x 490 / 1728 | 4 in x 4 in x 1/2 in | 12.760 |
| Shape by designation | Weight per foot from the name x length | W12x26 | 26.000 |
Steel fence posts and rails use the tube formulas. For the layout, see our fence calculator.
Worked examples
A plate 1/2 inch thick, 48 inches wide and 96 inches long has a volume of 2,304 cubic inches. At 0.2836 pounds per cubic inch, which is 490 divided by 1,728, it weighs 653.33 pounds, or 20.42 pounds per square foot. That is 296.35 kilograms.
| Shape | Size | Length | lb per ft | Total lb | Total kg | Short tons |
|---|---|---|---|---|---|---|
| Plate | 1/2 in x 48 in x 96 in | 1 piece | n/a | 653.33 | 296.35 | 0.3267 |
| Plate | 3/8 in x 12 in x 120 in | 1 piece | n/a | 153.13 | 69.46 | 0.0766 |
| Round bar | 3/4 in diameter | 20 ft | 1.503 | 30.07 | 13.64 | 0.0150 |
| Square bar | 1 in x 1 in | 10 ft | 3.403 | 34.03 | 15.43 | 0.0170 |
| Flat bar | 1/4 in x 2 in | 20 ft | 1.701 | 34.03 | 15.43 | 0.0170 |
| Hex bar | 1 in across flats | 12 ft | 2.947 | 35.36 | 16.04 | 0.0177 |
| Round pipe | 2.375 in OD, 0.154 in wall | 21 ft | 3.656 | 76.78 | 34.83 | 0.0384 |
| Rectangular tube | 4 in x 4 in, 1/4 in wall (sharp corners) | 20 ft | 12.760 | 255.21 | 115.76 | 0.1276 |
| Angle | 4 in x 4 in x 1/2 in (no fillets) | 20 ft | 12.760 | 255.21 | 115.76 | 0.1276 |
| Shape by designation | W12x26 (26 lb/ft in the name) | 20 ft | 26.000 | 520.00 | 235.87 | 0.2600 |
Rectangular tube and angle show the same 12.76 lb/ft here because a 4 x 4 x 1/4 tube and a 4 x 4 x 1/2 angle have equal sharp-corner area. Both read high against mill tables. A 3/4 inch round bar is 1.503 lb/ft and a 2.375 inch pipe with a 0.154 inch wall is 3.656 lb/ft.
Steel density by type
Carbon steel is computed at 490 pounds per cubic foot. Stainless steel is heavier, near 501 pounds per cubic foot. Use the custom field for an alloy with a published density. Iowa DOT uses 490 for steel in its computed weight table.
| Material | lb/ft3 | lb/in3 | kg/m3 | Source |
|---|---|---|---|---|
| Carbon steel | 490.0 | 0.2836 | 7,849 | Iowa DOT IM 569, Computed Weight table |
| Stainless steel | 501.3 | 0.2901 | 8,030 | Omni Calculator lists 8,030 kg/m3, converted here |
| Custom | 400 to 600 | n/a | n/a | Enter a published density from 400 to 600 lb/ft3 |
The kilograms per cubic meter for carbon steel is a unit conversion of 490 lb/ft3. It is not a separate source value.
Weight per foot of W, S and C shapes
The number after the x in a wide-flange name is the weight in pounds per foot. A W12x26 weighs 26 pounds per foot, so a 20 foot piece weighs 520.00 pounds. Enter that number in designation mode. The same rule applies to S, HP, C and MC shapes.
A 20 foot W12x26 comes to 235.87 kilograms or 0.26short tons. Pick "Shape by designation" in the calculator, type 26, and enter the length. This page does not carry the full AISC shape tables, so read the weight from the name or from your supplier list.
Plate weight per square foot
Steel plate weighs 40.83 pounds per square foot for each inch of thickness, from 490 divided by 12. A 1/2 inch plate weighs 20.42 pounds per square foot. Multiply by the area in square feet to get the weight of the plate.
| Plate thickness | lb per sq ft |
|---|---|
| 1/8 in | 5.10 |
| 3/16 in | 7.66 |
| 1/4 in | 10.21 |
| 3/8 in | 15.31 |
| 1/2 in | 20.42 |
| 3/4 in | 30.63 |
| 1 in | 40.83 |
Values are 40.83 times the thickness, rounded half up to two decimals.
Theoretical weight versus mill weight
The calculator gives theoretical weight from nominal size. Mills roll within tolerances, so delivered weight differs. ASTM A6/A6M Annex A1 lists the permitted variations in dimensions and mass. Check the mill ticket for exact weight before a lift or a haul.
Steel weight units and conversions
The calculator shows pounds, kilograms, short tons and metric tonnes. A short ton is 2,000 pounds. A metric tonne is 1,000 kilograms, which is 2,204.62 pounds. One pound is exactly 0.45359237 kilograms. A steel weight calculator in kg uses the same math with these factors.
| Unit | Equals |
|---|---|
| 1 lb | 0.45359237 kg |
| 1 kg | 2.20462 lb |
| 1 short ton | 2,000 lb = 907.18 kg |
| 1 metric tonne | 2,204.62 lb |
| 1 lb/ft | 1.48816 kg/m |
| 1 lb/ft3 | 16.0185 kg/m3 |
| 1 in | 25.4 mm |
Inputs are US inches and feet. A metric size input is not part of this version.
When to use another calculator
Use this page for the weight of plain steel shapes. Rebar has set bar numbers, steel studs and wood framing have their own counts, and structural steel member design needs an engineer. These calculators cover the nearby jobs.
- Rebar calculator: bar counts and sizes for slabs, footings and walls.
- Framing calculator: studs, plates and headers, including steel studs.
- Fence calculator: posts, rails and panels.
- Lumber calculator: the wood option, counted by board foot.
A structural steel calculator for beams and columns is planned. It is not on the site yet.
Methodology and sources
Published November 2026. Last updated November 2026. Next review November 2027. Weight is a theoretical estimate. It is not a lifting plan or a structural check. Pounds convert to kilograms at 0.45359237 kg per pound.
Reviews: volume calculators · 38 calculators reviewed
Alex Rivera is a Licensed Professional Engineer (PE) with 18 years of structural and civil engineering experience. He holds PE licenses in California (#C-89412) and Texas (#P.E.-98765). He previously served as Engineer of Record on 250+ residential foundation designs at Thornton Tomasetti. At CalcSummit, he writes and personally reviews every structural, concrete, rebar, deck, and framing calculator against current IRC and ACI 318 standards.
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