Looking to work with round bars? Whether you’re a seasoned professional or just starting out, it’s important to have a solid understanding of the specifications and weight calculations for these essential pieces of steel.
In this blog post, we’ll explore everything you need to know about round bars, including their dimensions, weight calculations, and more.
So, if you’re ready to dive into the world of round bars, keep reading!
What is round bar?
A round bar refers to a solid, long piece of steel that has a circular cross-section. The specifications for the round bar are expressed in millimeters and indicate its diameter. For example, a “50mm” round bar refers to a steel bar with a diameter of 50 millimeters.

How to calculate the weight of the round bar?
The calculation formula of the round bar is:
Weight (kg/m) = Outer diameter × External diameter ×0.00617
Round Bar Weight Calculator
According to the “GB/T702-2008” standard for hot-rolled steel bars, the diameter of these bars can range from 5.5mm to 310mm. The weight of the hot-rolled round steel bar can be delivered either as the actual weight or the theoretical weight.
The theoretical weight calculation formula for round steel bars is the same as that of wire rods, as both have the same shape and density. You can use the following round bar weight calculator to determine the weight of a round bar.
Round Bar Weight Chart
Diameter | Weight kg/m | Diameter | Weight kg/m |
5.5 | 0.186 | 13 | 1.04 |
6 | 0.222 | 14 | 1.21 |
6.5 | 0.26 | 15 | 1.39 |
7 | 0.302 | 16 | 1.58 |
8 | 0.395 | 17 | 1.78 |
9 | 0.499 | 18 | 2 |
10 | 0.617 | 19 | 2.23 |
* 11 | 0.746 | 20 | 2.47 |
12 | 0.888 | 21 | 2.72 |
22 | 2.98 | 63 | 24.5 |
* 23 | 3.26 | * 65 | 26 |
24 | 3.55 | * 68 | 28.5 |
25 | 3.85 | 70 | 30.2 |
26 | 4.17 | 75 | 34.7 |
* 27 | 4.49 | 80 | 39.5 |
28 | 4.83 | 85 | 44.5 |
* 29 | 5.18 | 90 | 49.9 |
30 | 5.55 | 95 | 55.6 |
* 31 | 5.92 | 100 | 61.7 |
32 | 6.31 | 105 | 68 |
* 33 | 6.71 | 110 | 74.6 |
34 | 7.13 | 115 | 81.5 |
* 35 | 7.55 | 120 | 88.8 |
36 | 7.99 | 125 | 96.3 |
38 | 8.9 | 130 | 104 |
40 | 9.86 | 140 | 121 |
42 | 10.9 | 150 | 139 |
45 | 12.5 | 160 | 158 |
48 | 14.2 | 170 | 178 |
50 | 15.4 | 180 | 200 |
53 | 17.3 | 190 | 223 |
* 55 | 18.6 | 200 | 247 |
56 | 19.3 | 220 | 298 |
* 58 | 20.7 | 250 | 385 |
60 | 22.2 |