Estimate the weight of steel and other metal stock before you order, lift or ship it. Choose the shape (plate, round, square or hex bar, pipe, rectangular tube or angle), enter the dimensions in mm or inches and the length, and get the weight in kilograms and pounds, per metre and for the whole quantity.
Last updated:
Shape
kg/m³
Enter your values to see the result.
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How to use the Steel Weight Calculator
Pick the shape of the stock.
Choose units and material; use custom density for other alloys.
Enter the cross-section dimensions (width and thickness, diameter, wall thickness, legs…).
Enter the length and quantity.
Read the weight in kg and lb, and compare other materials in the table.
Cross-section area formulas
Shape
Area A
Steel kg/m (dimensions in mm)
Plate / flat bar
W × T
0.00785 × W × T
Round bar
π × D² ÷ 4
0.006165 × D²
Square bar
S²
0.00785 × S²
Hex bar
(√3 ÷ 2) × AF²
0.006798 × AF²
Pipe
π ÷ 4 × (OD² − ID²)
0.02466 × t × (OD − t)
Rectangular tube
W × H − (W − 2t)(H − 2t)
0.0157 × t × (W + H − 2t)
Equal / unequal angle
t × (a + b − t)
0.00785 × t × (a + b − t)
Weight = A × length × density. The kg/m factors use 7,850 kg/m³; multiply by the density ratio for other metals (e.g. × 0.344 for aluminum).
Metal densities
Material
kg/m³
lb/in³
Carbon steel
7,850
0.2836
Stainless steel 304
7,930
0.2865
Stainless steel 316
7,980
0.2883
Cast iron (gray)
7,200
0.2601
Aluminum 6061
2,700
0.0975
Copper
8,960
0.3237
Brass
8,500
0.3071
Titanium (Ti-6Al-4V)
4,430
0.1600
Frequently asked questions
How do you calculate the weight of steel?
Weight = cross-sectional area × length × density. With the area in mm², length in mm and density in kg/m³, divide by 10⁹ to get kilograms. Carbon steel has a density of about 7,850 kg/m³ (0.2836 lb/in³).
How much does a steel plate weigh?
A carbon steel plate weighs 7.85 kg per square metre for every millimetre of thickness. A 10 mm plate is 78.5 kg/m², so a 1 × 2 m sheet weighs 157 kg. In imperial units, steel plate weighs about 40.8 lb per square foot per inch of thickness.
How do I calculate the weight of a steel pipe?
Use the ring area π/4 × (OD² − ID²) with ID = OD − 2 × wall. A quick metric formula is kg/m = 0.02466 × t × (OD − t) with OD and wall t in mm. For example a 2" Schedule 40 pipe (60.3 × 3.91 mm) weighs about 5.44 kg/m or 3.65 lb/ft.
What is the weight of a round steel bar?
kg/m = 0.006165 × D² with D in mm (from π/4 × D² × 7850 ÷ 10⁶). A 25 mm bar weighs about 3.85 kg/m; a 1 inch bar about 2.67 lb/ft.
Is stainless steel heavier than carbon steel?
Slightly. Stainless 304 is about 7,930 kg/m³ and 316 about 7,980 kg/m³, roughly 1–2% heavier than carbon steel. Aluminum is about one third of the weight of steel.
Why is my result slightly different from the supplier's table?
Rolled sections such as angles and tubes have rounded corners and root fillets that this calculator ignores (it uses sharp corners), and real stock has rolling tolerances. Differences of 1–3% are normal; use supplier data for exact shipping weights.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.