Rebar weight per metre calculator
The weight of one metre of reinforcing bar in kg = (diameter in mm)² ÷ 162. A 16 mm bar weighs about 1.58 kg per metre; the calculator multiplies this by the bar length and the number of bars to give the total in kg and tonnes.
Calculator
- Total weight
- 1,896 kg (1.9 t)
- Weight per metre
- 1.58 kg/m
- Weight of one bar
- 18.96 kg
Method, step by step
- Square the bar diameter in mm and divide by 162 to get the weight per metre in kg.
- Multiply by the bar length in metres to get the weight of one bar.
- Multiply by the number of bars for the total weight, and divide by 1000 for tonnes.
Worked example
Inputs
- Bar diameter (mm): 16
- Bar length (m): 12
- Number of bars: 100
- Weight per metre = D² ÷ 162 = 16² ÷ 162 = 1.58 kg/m.
- One bar = 1.58 × 12 = 18.96 kg.
- Total = 18.96 × 100 = 1,896 kg = 1.9 t.
Result
- Total weight
- 1,896 kg (1.9 t)
- Weight per metre
- 1.58 kg/m
- Weight of one bar
- 18.96 kg
Rebar weight table by diameter
| Diameter (mm) | Weight per metre (kg) | Weight of a 12 m bar (kg) |
|---|---|---|
| 6 | 0.222 | 2.67 |
| 8 | 0.395 | 4.74 |
| 10 | 0.617 | 7.41 |
| 12 | 0.889 | 10.67 |
| 14 | 1.21 | 14.52 |
| 16 | 1.58 | 18.96 |
| 18 | 2 | 24 |
| 20 | 2.469 | 29.63 |
| 22 | 2.988 | 35.85 |
| 25 | 3.858 | 46.3 |
| 28 | 4.84 | 58.07 |
| 32 | 6.321 | 75.85 |
Assumptions and default ratios
| Ratio | Default value |
|---|---|
| Weight-per-metre divisor (D² ÷ divisor) | 162 number |
- The formula approximates a round section (π × D² ÷ 4) times a steel density of about 7850 kg/m³; actual weights may differ slightly by product and tolerance.
- D is the nominal bar diameter in millimetres.
Frequently asked questions
How much does one metre of 12 mm rebar weigh?
12² ÷ 162 = 144 ÷ 162 = about 0.889 kg per metre, so a 12 m bar weighs about 10.67 kg. The table below covers the other diameters.
Where does 162 come from?
From the section area π × D² ÷ 4 (in mm²) times a steel density of about 7850 kg/m³: about 0.00617 × D², or roughly D² ÷ 162.
How many bars are there in a tonne?
Divide 1000 by the weight of one bar. A 12 m bar of 16 mm weighs about 18.96 kg, so a tonne holds about 52 bars.
Add the result to your project BOQ in Ta3mir
In Ta3mir the same calculators work inside your project: send a result to a BOQ line in one click and save your own default ratios for every calculation.