TMT Steel Bar Weight Calculator
Calculate steel bar weight per metre, per rod and total, plus cost, using the standard D²/162 formula.
Built & reviewed by Ankit Madia, Founder & Markets Trader
TMT Steel Bar Weight Calculator
This tool converts the number and size of steel bars into total weight and cost. It is used by site engineers, contractors and steel traders to estimate reinforcement quantities and to cross-check the weight billed by the mill or dealer. Steel is sold by weight, so knowing the exact kilograms matters for both ordering and payment.
The Weight Formula
Weight per metre (kg) = D² / 162.28
Total weight = Weight per metre × Total length (m)
D is the bar diameter in millimetres. The constant 162.28 is derived from the density of steel (7850 kg/m³) and the cross-sectional area of a round bar. A 12 mm bar therefore weighs 0.888 kg per metre.
Standard Bar Weights (kg per metre)
| Diameter | Weight / m | Weight / 12 m rod | Rods per tonne |
|---|---|---|---|
| 6 mm | 0.222 kg | 2.66 kg | ~375 |
| 8 mm | 0.395 kg | 4.74 kg | ~211 |
| 10 mm | 0.617 kg | 7.40 kg | ~135 |
| 12 mm | 0.888 kg | 10.66 kg | ~94 |
| 16 mm | 1.580 kg | 18.96 kg | ~53 |
| 20 mm | 2.469 kg | 29.62 kg | ~34 |
| 25 mm | 3.858 kg | 46.30 kg | ~22 |
| 32 mm | 6.321 kg | 75.85 kg | ~13 |
Practical Notes
- Standard TMT bar length in India is 12 metres.
- Bars are grouped in grades like Fe 500 and Fe 550, which affect strength, not weight per metre.
- Actual weight can vary ±3% under IS 1786 tolerance — mills bill on rolled weight.
- For a cutting list, add up the length of every bar mark, then apply the per-metre weight.