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Round Bar Weight Calculator

Work out the weight of round, square, hexagon or flat bar from its size and length — per metre, per bar and total, for any grade.

Weight per metre
3.85 kg/m
Per bar (6 m): 23.13 kg
Total for 1: 23.13 kg
Ø25 mm round bar

Results are indicative; confirm exact mill weights on your MTC. For pipe use the pipe weight calculator.

/ How it works

How to calculate round bar weight

Round bar weight per metre is the cross-sectional area × density. With diameter in mm and density in kg/m³:

kg/m = (π ÷ 4) × diameter² × density ÷ 1,000,000

So a 25 mm carbon-steel bar is 3.85 kg/m; a 20 mm bar is 2.47 kg/m. Multiply by length for the bar weight. Select the shape above — square uses side², hexagon uses 0.866 × A/F², flat uses width × thickness.

/ FAQ

Common questions

How do you calculate the weight of a round bar?
Weight per metre = (π ÷ 4) × diameter² (mm) × density (kg/m³) ÷ 1,000,000. Multiply by the length in metres for the bar weight.
What is the weight of a 25 mm steel round bar per metre?
About 3.85 kg/m in carbon steel; a standard 6 m bar is ~23.1 kg.
What is the weight of a 20 mm round bar?
2.47 kg/m for carbon steel (0.785 × 20² × 7850 ÷ 1,000,000).
Does stainless round bar weigh more than carbon?
Slightly — stainless is ~2% denser, so a same-diameter stainless bar weighs about 2% more. Select the grade above.
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