What’s the formula for steel weight?

Weight (kg) = cross-sectional area (mm²) × length (m) × density ÷ 1000. A 1 mm² cross-section 1 m long is 1 cm³, so steel with a density of 7.85 weighs 7.85 g per cm³. For example, a φ16 round bar has an area of π/4 × 16² ≈ 201.1 mm², so 201.1 × 7.85 ÷ 1000 ≈ 1.58 kg/m.

How much does a 3×6 ft steel plate weigh?

A 3×6 sheet is 914×1829 mm (about 1.672 m²), so its weight is “7.85 × thickness (mm) × 1.672” kg: about 21.0 kg at 1.6 mm, 30.2 kg at 2.3 mm, 42.0 kg at 3.2 mm, 59.0 kg at 4.5 mm, 78.7 kg at 6 mm, and 118 kg at 9 mm. A 4×8 sheet (1219×2438 mm) is about 2.97 m², so about 74.7 kg at 3.2 mm.

What’s the formula for square tube weight?

The JIS G 3466 (square steel pipe for general structure) formula is unit mass (kg/m) = 0.0157 × t × (A + B − 3.287t), where A and B are the sides and t the wall thickness in mm. It takes the outer corner radius as twice the thickness and subtracts the rounded corners. □-50×50×2.3 is 0.0157 × 2.3 × (100 − 7.56) ≈ 3.34 kg/m, and □-100×100×3.2 is about 9.52 kg/m.

How much does an H-beam weigh per meter?

The cross-sectional area is “2 × B × t2 + (H − 2 × t2) × t1 + (4 − π) × r²”; multiply by 7.85 and divide by 1000 for kg/m. H-100×100×6×8 (r=8) is about 16.9 kg/m, H-200×100×5.5×8 about 20.9 kg/m, and H-300×150×6.5×9 (r=13) about 36.7 kg/m. You can check typical sizes under H-beams in the “Standard size charts”.

How heavy are stainless steel and aluminum compared with steel?

At the same dimensions, weight is proportional to density. Stainless SUS304 is 7.93, about 1.01× steel (7.85); SUS430 is 7.70, about 0.98×; aluminum A5052 is 2.68, about 0.34× (about 1/3); brass is about 8.47, about 1.08×; copper is 8.89, about 1.13×; and titanium is 4.51, about 0.57×. The “Compare materials” tab lists weights for the same dimensions side by side.

How much does 4.5 mm checker plate weigh?

Per the JIS guideline, checker plate weighs “7.85 × thickness + 3 (kg/m²)”. At 4.5 mm that’s 7.85 × 4.5 + 3 ≈ 38.3 kg/m², so one 3×6 sheet (914×1829 mm) is about 64.1 kg and a 4×8 sheet about 113.9 kg. The thickness is the base thickness excluding the raised pattern, which adds about 3 kg per m².

How much do D10 and D13 rebar weigh?

Per the JIS G 3112 unit masses, D10 is 0.560 kg/m, D13 0.995 kg/m, D16 1.56 kg/m, D19 2.25 kg/m, D22 3.04 kg/m, and D25 3.98 kg/m. A standard 5.5 m D13 bar weighs about 5.47 kg, and 1 t of D13 is about 1,005 m.

Steel & Metal Weight Calculator | kg/m and Charts for Flat Bar, Square Tube, H-Beam, Angle, Checker Plate & Rebar

The steel & metal weight calculator works out the weight of steel plate (PL), checker plate, flat bar, round bar, square bar, hex bar, deformed bar (rebar D10–D51), round pipe (STK, SGP), square tube (STKR), angle, channel, H-beam, and C-channel (lipped channel) from dimensions (mm), length, and quantity. It gives the cross-sectional area, weight per meter (kg/m), weight per piece or sheet, and the total, and if you enter a price per kg, the cost too. Besides steel (SS400, density 7.85), materials include stainless SUS304, SUS316, SUS430, aluminum A1100, A5052, A6063, A7075, copper, brass, titanium, cast iron, lead, acrylic, polycarbonate, MC nylon, or any density. Fillet radii for H-beams and angles, the corner radius of square tubes (JIS G 3466), the bend radius of C-channels (JIS G 3350), and “7.85t + 3” for checker plate are built into the formulas, so values closely match JIS unit masses. It also includes back-calculating length from weight, a table comparing weights by material at the same dimensions, single-sheet weights for 3×6, 4×8, and 5×10 ft plates, and weight charts for standard sizes of round bar, flat bar, square tube, SGP, angle, C-channel, H-beam, and rebar.

Calculate the weight of steel or metal

Choose a shape and material, then enter dimensions (mm), length, and quantity to get the cross-sectional area, weight per meter (kg/m), weight per piece or sheet, and the total. Enter a price per kg to see the cost too.

Shape (type of steel)

Material

Structural steel, carbon steel for machine structures, cold- and hot-rolled sheet

Flat bar

FB-6×50

Thickness t

Width W

Length (each)

Quantity

pcs

Length:

Result

Flat bar FB-6×50 · Steel (SS400, S45C, SPCC, SPHC) (density 7.85)

Total (1 pcs)

12.95kg

Weight per piece

12.95kg

Length 5.5 m

Unit weight

2.355kg/m

About 0.425 m per kg

Cross-sectional area

3cm²

300mm²

Formula

t × W × length × density

Weight (kg) = area (mm²) × length (m) × density ÷ 1000 = 300 × 5.5 × 7.85 ÷ 1000 = 12.953 kg

Unit price (per kg, optional)

/kg

Back-calculate length from weight

20 kg is a length of 8,493 mm (8.493 m) / for 1.54 pcs

Assumptions

These are theoretical weights from dimensions. Actual products vary by a few percent due to rolling tolerances, galvanizing, and paint.
For H-beams, angles, and channels, including R (fillet) gives values nearly identical to JIS section tables. Channels ignore flange taper, so they may come out slightly heavier than the JIS table.
Square tubes use the JIS G 3466 formula with the outer corner R at twice the wall thickness, and C-channels follow JIS G 3350 with the inner bend R equal to the thickness.
Checker plate uses the JIS “7.85 × thickness + 3 (kg/m²)”. Non-steel checker plates are estimates converted by density ratio.
Enter all dimensions in mm, including length (5.5 m is 5500).

What you enter is only saved in this browser and is not sent to a server.

ABOUT

About Steel & Metal Weight Calculator | kg/m and Charts for Flat Bar, Square Tube, H-Beam, Angle, Checker Plate & Rebar

The steel & metal weight calculator finds the weight of steel plate, checker plate, flat bar, round bar, square and round tubes, angles, channels, H-beams, C-channels, rebar, and more from dimensions and length. Weight (kg) is “cross-sectional area (mm²) × length (m) × density ÷ 1000”, and the density of steel (SS400) is 7.85. For example, a 6×50 flat bar is 300 mm², so 2.355 kg/m and about 12.95 kg for 5.5 m; 3.2 mm steel plate is 25.12 kg per m², so one 3×6 ft sheet (914×1829 mm) is about 42 kg. The formulas include fillet radii for H-beams and angles, corner radii for square tubes (0.0157t(A+B−3.287t) from JIS G 3466), and bend radii for C-channels, giving values nearly identical to JIS unit masses (H-100×100×6×8 is 16.9 kg/m). You can switch materials to stainless SUS304 (7.93), aluminum A5052 (2.68), brass, copper, titanium, plastics, and more, and calculate cost from a unit price or back-calculate length from weight.

How to use Steel & Metal Weight Calculator | kg/m and Charts for Flat Bar, Square Tube, H-Beam, Angle, Checker Plate & Rebar

1In the “Calculate weight” tab, choose a shape such as plate, flat bar, square tube, or H-beam
2Choose a material (steel, SUS304, aluminum, brass, etc.). For materials not listed, enter a density with “Enter density”
3Enter the dimensions (mm) matching the symbols in the diagram, then the length (mm) and quantity. For plates, you can also pick standard sizes (3×6, 4×8, 5×10) with buttons
4Read the total, weight per piece (sheet), kg/m (kg/m² for plates), and cross-sectional area. The formula is shown below
5If needed, enter a price per kg for the cost, or enter a weight to back-calculate the required length
6To find standard sizes, press a row in the “Standard size charts” to load it
7Paste into a quote or notes with “Copy result”, or share with “Copy the URL for these settings”

Great for

Check the weight of flat bar, square tube, or angle for DIY to see if you can carry it or fit it in a car
Find out how many kg one 3×6 or 4×8 steel sheet weighs, or the weight of 4.5 mm checker plate
Calculate material cost in a quote from steel weight (tonnage) and price per kg
Calculate the weight of H-beam or C-channel beams to plan for cranes, rigging, and frame loads
Compare how much lighter (or heavier) it gets when switching from steel to stainless or aluminum
Estimate the weight of scrap or offcuts from dimensions for a rough buyback price
Calculate the rebar weight (kg, t) of reinforcement from the number of D10 or D13 bars

Good to know

These are theoretical weights based on dimensions. Actual products vary by a few percent due to rolling tolerances, plating, and paint, and may differ slightly from manufacturers’ catalog values.
For H-beams, angles, and channels, including the fillet radius (R) gives values nearly identical to JIS section property tables. Setting R to 0 gives the theoretical value with square corners.
Channels ignore the flange taper, so results may come out about 0.3% heavier than the JIS table.
Checker plate is calculated with the JIS G 3101 mass guideline “7.85 × thickness + 3 (kg/m²)”. Aluminum and stainless checker plates are estimates converted by the density ratio.
Rebar (deformed bar) uses the nominal unit masses in JIS G 3112 (D13 = 0.995 kg/m, etc.).
Dimensions and prices you enter are saved only in this device’s browser and not sent to a server.

Questions this tool answers

Use Steel & Metal Weight Calculator | kg/m and Charts for Flat Bar, Square Tube, H-Beam, Angle, Checker Plate & Rebar for searches like these:

I want to calculate flat bar weight from dimensions
I want to calculate square tube weight with the formula
I want to know the weight of a 3×6 steel plate
I want to know the weight per meter of an H-beam
I want to calculate checker plate weight
I want to compare the weight of SUS304 and aluminum
I want to estimate material cost from steel weight
I want to know the unit weight of D13 rebar

FAQ

What’s the formula for steel weight?: Weight (kg) = cross-sectional area (mm²) × length (m) × density ÷ 1000. A 1 mm² cross-section 1 m long is 1 cm³, so steel with a density of 7.85 weighs 7.85 g per cm³. For example, a φ16 round bar has an area of π/4 × 16² ≈ 201.1 mm², so 201.1 × 7.85 ÷ 1000 ≈ 1.58 kg/m.
How much does a 3×6 ft steel plate weigh?: A 3×6 sheet is 914×1829 mm (about 1.672 m²), so its weight is “7.85 × thickness (mm) × 1.672” kg: about 21.0 kg at 1.6 mm, 30.2 kg at 2.3 mm, 42.0 kg at 3.2 mm, 59.0 kg at 4.5 mm, 78.7 kg at 6 mm, and 118 kg at 9 mm. A 4×8 sheet (1219×2438 mm) is about 2.97 m², so about 74.7 kg at 3.2 mm.
What’s the formula for square tube weight?: The JIS G 3466 (square steel pipe for general structure) formula is unit mass (kg/m) = 0.0157 × t × (A + B − 3.287t), where A and B are the sides and t the wall thickness in mm. It takes the outer corner radius as twice the thickness and subtracts the rounded corners. □-50×50×2.3 is 0.0157 × 2.3 × (100 − 7.56) ≈ 3.34 kg/m, and □-100×100×3.2 is about 9.52 kg/m.
How much does an H-beam weigh per meter?: The cross-sectional area is “2 × B × t2 + (H − 2 × t2) × t1 + (4 − π) × r²”; multiply by 7.85 and divide by 1000 for kg/m. H-100×100×6×8 (r=8) is about 16.9 kg/m, H-200×100×5.5×8 about 20.9 kg/m, and H-300×150×6.5×9 (r=13) about 36.7 kg/m. You can check typical sizes under H-beams in the “Standard size charts”.
How heavy are stainless steel and aluminum compared with steel?: At the same dimensions, weight is proportional to density. Stainless SUS304 is 7.93, about 1.01× steel (7.85); SUS430 is 7.70, about 0.98×; aluminum A5052 is 2.68, about 0.34× (about 1/3); brass is about 8.47, about 1.08×; copper is 8.89, about 1.13×; and titanium is 4.51, about 0.57×. The “Compare materials” tab lists weights for the same dimensions side by side.
How much does 4.5 mm checker plate weigh?: Per the JIS guideline, checker plate weighs “7.85 × thickness + 3 (kg/m²)”. At 4.5 mm that’s 7.85 × 4.5 + 3 ≈ 38.3 kg/m², so one 3×6 sheet (914×1829 mm) is about 64.1 kg and a 4×8 sheet about 113.9 kg. The thickness is the base thickness excluding the raised pattern, which adds about 3 kg per m².
How much do D10 and D13 rebar weigh?: Per the JIS G 3112 unit masses, D10 is 0.560 kg/m, D13 0.995 kg/m, D16 1.56 kg/m, D19 2.25 kg/m, D22 3.04 kg/m, and D25 3.98 kg/m. A standard 5.5 m D13 bar weighs about 5.47 kg, and 1 t of D13 is about 1,005 m.

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