Steel bar weight calculator
Find the weight of reinforcement bars by diameter, length and number of bars, using the standard D squared over 162 formula.
How much does a 12 m bar of 12 mm steel weigh?
A 12 mm bar weighs about 0.889 kg per metre, so one 12 m bar weighs about 10.7 kg, and a bundle of 10 such bars weighs about 107 kg. Choose your own bar size, length and number above.
How is the weight worked out?
The weight of a steel bar in kilograms per metre is the square of its diameter in millimetres divided by 162. The calculator multiplies that by the bar length and the number of bars.
Weight per metre of common bars
| Diameter | Weight per metre (kg) | One 12 m bar (kg) |
|---|---|---|
| 6 mm | 0.222 | 2.7 |
| 8 mm | 0.395 | 4.7 |
| 10 mm | 0.617 | 7.4 |
| 12 mm | 0.889 | 10.7 |
| 16 mm | 1.580 | 19.0 |
| 20 mm | 2.469 | 29.6 |
| 25 mm | 3.858 | 46.3 |
| 32 mm | 6.321 | 75.9 |
What does it assume?
- Plain steel density of 7,850 kg per cubic metre, which gives the D²/162 formula.
- Laps, hooks, bends and cutting waste are not included. Your bar bending schedule gives the real lengths.
- The mass of real bars can differ from this formula within the tolerances in IS 1786, and dealers bill by actual weight.
Sources
- IS 1786, High Strength Deformed Steel Bars and Wires for Concrete Reinforcement (nominal sizes and mass).
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General information only. It is not a structural design or professional advice. Ask a licensed structural engineer or architect to check your plans and site.