HOW TO CALCULATE OF UNIT WEIGHT OF STEEL BARS

CALCULATION OF UNIT WEIGHT OF STEEL BARS:

After estimating it is very important  to know the unit weight of steel bars, because we estimate as 100 meter 20mm dia bar or 100 feet 16mm dia bar, etc.
But steel bar suppliers will not understand this notation, they measure the steel bars in weight. So we have to order them in kg or quintal or ton. In this article, we will discuss how to calculate unit weight of steel bars of different diameter.

The formula is W = D²L / 162

where,

W = weight of steel bars.
D = Diameter of steel bars in mm.
L = Length of bars in meter.

Example 1 : Calculate the weight of 60 meter long 12mm dia bar.

Here, D = 12mm.
L = 100m.
We know that, W = D²L / 162

W = 12² x 60/162 = 53 kg 

Weight of 60 m 12mm dia bar is 53 kg.

Let's look for another example.

Example 2 : Calculate the weight of 100 m 16mm dia bar.

Here, D = 16mm

L = 100m

W = 16² x 100/162 = 158 kg 

If we put 1meter length for each diameter of steel bar in the formula then we will get the unit weight.

• 10mm dia bar = 10² x 1/162 = 0.617 kg/m
• 12mm dia bar = 12² x 1/162 = 0.888 kg/m
• 16mm dia bar = 16² x 1/162 = 1.580 kg/m
• 20mm dia bar = 20² x 1/162 = 2.469 kg/m

If we multiply the length of bars with this unit weight we will get the total weight of steel bars.

For example, total weight of 1000 meter long 20mm dia steel bar is,

1000 x 2.469 = 2469 kg.

Using the same method we can calculate the unit weight of different steel bars.

Here I have calculated in meter but we can also calculate in foot. To calculate in foot we have to use the following formula:

W = D²L / 533

Where, 
D = Diameter of bars in mm.
L = Length of bars in foot.