Steel is the leading composite material for RCC Structures. Usually, the steel is used for structural construction such as footings, slabs, etc. It uses widely in residential, commercial, and mega projects. Accordingly, calculating the weight of steel is a prime factor in modern construction.
Rebars are mostly available in the round section having a length of 12m or 40 feet. The Kg or Ton is the measuring unit that use to procure, purchase and transport steel bars. The base variable factor for determining the weight of Steel is the diameter of the reinforcing bar either in mm – millimeters or # (No.) of Bar in inches.
The Steel Reinforcement Weight calculates for:
- Structural Designing
- Bar Bending Schedule for Steel Cutting and Bending
- Purchasing and Billing
The formula for Calculating the Weight of Steel
If you do not belong in the rebar business or estimating jobs then it is difficult to remember the weight of different types of bars. It is also a problem to recall the exact bar value when you are going to use it. Mostly, the ASTM standard charts are used to acquire the actual weight of steel.
Whether you are estimating the quantities of reinforcement or calculating it in Kg, you are not having the commercial rebar weight chart time with you. To overcome this problem, the following derived formula is used for calculating it. Whether you are a Project Engineer or Quantity Surveyor, this formula is going to help you out.
Derivation for Weight Calculating Formula
The derived formula is based on the average density or unit weight of steel, i.e., 7850 Kg/m3. It is to note here that the density of steel varies from 7750 Kg/m3 to 8050 Kg/m3 based on the alloy components consumed during its manufacturing.
The derivation is as below:
The above equation can be used to obtain the mass of rebar in Kg/m just by simply entering the dia of the bar in mm. You can also use the Steel Bar Weight Calculator to find out the structural reinforcement in Kg/m.
ASTM Standard Weights for Steel Reinforcement
However, you can also use the exact values for weight in your calculation while preparing Bar Bending Schedules. The following are the tables providing the values in Kg/m following the ASTM Standards.
Dia of Bar |
Weight (Kg/m) |
10mm |
0.617 |
12mm |
0.888 |
16mm |
1.578 |
20mm |
2.466 |
25mm |
3.853 |
28mm |
4.834 |
32mm |
6.313 |
36mm |
7.99 |
40mm |
9.865 |
The following is the table providing the values for structural rebar weight in Kg/ft. As in many countries, the imperial system is the major measuring unit for the preparation of drawings and structural detailing. Therefore, the below table will help you to pick out the exact weight in Kg/ft following ASTM Standards.
Dia of Bar |
Weight (Kg/ft) |
#3 |
0.171 |
#4 |
0.303 |
#5 |
0.473 |
#6 |
0.681 |
#7 |
0.927 |
#8 |
1.211 |
#9 |
1.542 |
#10 |
1.952 |
#11 |
2.41 |
Using this formula is helpful in all ways to minimize time-consuming practice. You can also use this equation in preparing Bar Bending Schedule in Excel.
I hope this article will help you to get the weight of steel easily. If you have queries, you can share them in the comment section below or contact me. Don’t forget to share it with your friends and colleagues to give them an easy way in resolving the problems related to the rebar weight calculations.
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Thanks for your expression of interest!