The weight of steel calculation is very important, but before calculating weight it is important to properly understand the properties of steel. In steel, the carbon is between 0.002 % to 2.14 % by its own weight of the steel. The carbon ratio value of steel may vary and it depends on which steel alloying element is going using such as carbon, nickel, chromium, manganese, iron, and other alloying elements.

Basically Iron with alloy carbon is present in the steel, which doesn’t undergo any eutectic reactions but cast iron always undergoes a eutectic reaction. If the carbon content is too low present in the steel. The iron will be soft, weak, and also very ductile in its properties.

As we mention early the carbon will be in the weight of steel up to 2.14 % of its own weight. The weight of steel bars can be calculated theoretically as well as physically. In this article, we are going to discuss academic methods. The weight of the steel bar can be calculated in two ways.

1- By Density of steel

2- By Formula

1- By Density of steel

It is very important to know the unit weight of steel bars as well as rectangular steel plates, in kilograms and in Tons. The given below formula is most commonly used in the calculation of rectangular steel plate weight calculation.

Note: The Density of steel is 7850 kg/m³


 Weight = Volume X Density


 Let’s suppose we have a rectangular steel plate having a length of 1 m or a Width of 0.5 m the Depth (Thickness) is 0.3 m. To calculate the theoretical unit weight of a rectangular steel plate?

Given Data:

Length       = 1 m (1,000 mm)

Width        = 0.5 m (500 mm)

Thickness = 0.3 m (300 mm)


First, calculate the volume of the steel sheet.

Volume = (L x W x T)

= 1 m x 0.5 m x 0.3 m

0.15 m^3.

Weight = Volume x Density

= o.15 x 7850

1177.5 kg. Ans.

Note: If you are calculating the weight of the circular steel reinforcement bar then calculate its volume by using this formula (πD^2/4) and then just multiply by the density of steel which is 7850 kg/m^3.

2- By Formula

To calculate the weight of circular reinforcement bars etc. The given below formula is most commonly used at site level steel weight calculation which is.


Weight = (D²/162) x Length


Let’s Suppose we have a circular reinforcement bar that has a diameter (D) of 12 mm and having a length of 10 m.

Given Data:

Diameter = 12 mm

Length      = 10 m


By using the steel weight formula put the given values.

Weight = (D²/162) x Length

= (12 x 12/162) x 10

8.8 kg Ans…

So the 10-meter long bar has a diameter of 12 mm its weight will be 8.8 kg. So in this way, we can calculate the theoretical weight of steel at the site.

Note: If the properties of the steel change its physical weight will also be changed.

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