mild steel round bar weight calculator

Enter the dimensions of a mild steel round bar and this works out its volume and weight. Plain carbon structural steel such as A36, S275 or 1018. Alloying moves the density by well under 1%.

Diameter

Length

Number of pieces

Total weight

3.853 36kg

≈ Rounded mild steel round bar weight Show in

Weight of one round bar: 3.853 36
Volume of one piece: 490.874
Weight per metre of length: 3.853 36 kg/m
Density used: 7850 kg/m3

Show the working

Diameter = 25
Length = 1000
Number of pieces = 1
volume_mm3 = pi * (25/2)^2 * 1000 = 490 874
Volume of one piece = 490 874 / 1000 = 490.874
Density used = 7850 = 7850
Weight of one round bar = 490 874 * 7850 / 1e9 = 3.853 36
Total weight = 3.853 36 * 1 = 3.853 36
Weight per metre of length = 490 874 / 1000 * 1000 * 7850 / 1e9 = 3.853 36

Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.

Scenarios & local history

Compare a saved scenario

Recent calculations

The formula

Volume = pi x (diameter / 2)^2 x length
Weight = volume x density, with density = 7850 kg/m3
One cubic millimetre of a material at 1000 kg/m3 weighs exactly one milligram, so the millimetre-to-kilogram step is a shift of the decimal point rather than a rounded factor.

Plain carbon structural steel such as A36, S275 or 1018. Alloying moves the density by well under 1%.

Dimensions are nominal. Mill tolerances on thickness, and the corner radii on formed sections, both move the real weight by a percent or two.

Every field takes inches or feet as readily as millimetres: change the unit next to it and the conversion is done exactly before the arithmetic starts.

Frequently asked

What is the density of mild steel?

7850 kg/m3, which is 7.850 g/cm3. Plain carbon structural steel such as A36, S275 or 1018. Alloying moves the density by well under 1%.

How do you calculate the weight of a mild steel round bar?

Volume = pi x (diameter / 2)^2 x length. Multiply the volume by the density of mild steel, 7850 kg/m3, taking care that both are in the same unit system.

Can I enter dimensions in inches?

Yes. Each dimension field has its own unit selector, and inch, foot, millimetre, centimetre and metre entries are all converted exactly before anything is multiplied.

Where the numbers come from

Densities are nominal room-temperature values for the grade named, drawn from the usual mill and handbook figures.