Rebar Weight Calculator
Work out the weight of rebar based on bar size and length for your concrete project with this free rebar weight calculator.
Enter Values
Minimum 1
Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.
How to use this calculator
- Enter the bar diameter (mm) and length per bar (m).
- Optionally set the number of bars for the total.
How it works
Steel rebar weighs about d² ÷ 162 kg per metre (d in mm). Multiply by length and quantity for the total mass.
Worked example
12 mm bar, 6 m. ≈ 0.889 kg/m, so about 5.33 kg per bar.
Common mistakes
- Entering the diameter in cm or metres — it should be millimetres.
- Forgetting laps and wastage when ordering.
Frequently asked questions
How is rebar weight calculated?
From bar diameter and length: weight per metre ≈ diameter² ÷ 162 in kg for metric bars. The tool totals it across your bar schedule.
Why does rebar weight matter?
Steel is sold and priced by weight, and weight checks help confirm the right bar sizes were delivered for the design.
Where does ÷ 162 come from?
It's the steel-density shortcut: area (πd²/4 mm²) × 7850 kg/m³ works out to about d² ÷ 162 kg per metre.
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Cite this tool
Zerdly. (2026). Rebar Weight Calculator. Retrieved from https://www.zerdly.com/tools/rebar-weight-calculator/
Tip: Enter any known values to calculate the remaining results.
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