Steel / TMT Weight Calculator
Estimate TMT reinforcement bar weight using diameter, bar length and number of bars.
Theoretical steel weight
Enter values
How this calculator works
Theoretical unit weight is calculated from the cross-sectional area of a round steel bar and steel density of 7,850 kg/m³.
This is approximately equivalent to the commonly used d² / 162 kg per metre shortcut.
Example
A 12 mm bar has a theoretical weight of about 0.888 kg per metre. Multiply by bar length and quantity for total weight.
Frequently asked questions
Is d²/162 exact?
It is a convenient field approximation. This calculator uses the geometric density formula with 7,850 kg/m³.
Will actual bar weight be exactly the same?
Manufacturing tolerances can cause small differences. Use supplier weight for procurement reconciliation.
Can I use this for plain round bars?
Yes, for theoretical mass based on nominal diameter.