Unit Weight of Steel Reinforcement Calculator | BBS Course

Unit Weight of Steel Reinforcement

Standard Formula

D² / 162

Unit Weight of Steel Bar in kg/m

Derivation of Formula

Step 1: Unit Weight = Volume × Density

Step 2: Volume of Steel Bar = Area × Length

Step 3: Area of Circular Bar = (π/4) × D²

Step 4: Considering length = 1 meter

Volume = (π/4 × D² × 1)

Step 5: Density of Steel = 7850 kg/m³

Final Formula:

Unit Weight = D² / 162 kg/m

Important Note: Diameter (D) should always be entered in millimeters (mm).

The formula D²/162 is a simplified practical formula commonly used in RCC design, Bar Bending Schedule (BBS), estimation, and site calculations.

Calculator

Enter Bar Diameter (mm)

Calculation Result

Unit Weight of Standard Bars

Bar Diameter	Formula	Unit Weight (kg/m)
8 mm	(8 × 8)/162	0.395
10 mm	(10 × 10)/162	0.617
12 mm	(12 × 12)/162	0.889
16 mm	(16 × 16)/162	1.580
20 mm	(20 × 20)/162	2.470
25 mm	(25 × 25)/162	3.858
32 mm	(32 × 32)/162	6.320

Reference Codes

• IS 1786 – High Strength Deformed Steel Bars and Wires.
• IS 456 : 2000 – Plain and Reinforced Concrete Code.
• SP 34 – Handbook on Concrete Reinforcement and Detailing.

Developed By

Mohan Dangi (Gold Medalist)