Steel Weight Calculator
Add your bars (diameter, length, number). Get the weight of each line, the total in kg and tonnes, and the cost. Uses W = D²/162 kg per metre.
1. Your bars
| Dia (mm) | Length of one bar (m) | No. of bars | kg/m | Weight |
|---|
Weights are nominal (D²/162). Real TMT bars can vary within IS 1786 tolerance. Rate is only an example; use your local price.
2. Quick: steel plate / flat weight
Plate weight = Length × Width × Thickness (mm) × 7.85 kg.
How this steel weight calculator works
The weight of a round steel bar per metre is W = D² ÷ 162 kg/m, where D is the diameter in mm. It comes from the density of steel (7,850 kg/m³) and the area of a circle. The calculator multiplies this by the length and number of bars for each line, adds all lines, and then adds your wastage percentage for ordering.
| Dia (mm) | 6 | 8 | 10 | 12 | 16 | 20 | 25 | 32 |
|---|---|---|---|---|---|---|---|---|
| kg/m | 0.222 | 0.395 | 0.617 | 0.888 | 1.58 | 2.47 | 3.85 | 6.31 |
| 12 m bar (kg) | 2.66 | 4.74 | 7.40 | 10.66 | 18.96 | 29.64 | 46.20 | 75.72 |
Want the full explanation, the derivation, tolerances and site examples? Read our guide: Unit Weight of Steel Bars: D²/162 Formula & Chart. Making a full bar bending schedule? Use the BBS Generator, or see all civil engineering calculators.
FAQ
How do I calculate the weight of 12 mm steel bar?
12 × 12 ÷ 162 = 0.888 kg per metre. One 12 m bar weighs about 10.66 kg.
How much wastage should I add?
About 3–5% for cutting waste is common. Use more for small jobs with many short bars.
Is the result accurate for TMT bars?
It gives the nominal weight used for BBS and estimates. Actual bars can be slightly heavier or lighter within the IS 1786 tolerance, so weigh sample bars when you check a delivery.