Steel Rebar Weight Calculator
This free steel rebar weight calculator estimates the weight of reinforcing bar from its diameter (or bar size) and length. It supports both metric bar sizes and US bar numbers for concrete work.
How it works & formula
Rebar weight per metre is W (kg/m) = d² × 0.006165 (d in mm), the same as round bar. US bar numbers give the diameter in eighths of an inch (a #5 bar is 5/8 inch).
Reference data
Standard rebar unit weights:
| Metric | US size | Weight (kg/m) | Weight (lb/ft) |
|---|---|---|---|
| 10 mm | #3 | 0.62 | 0.376 |
| 13 mm | #4 | 0.99 | 0.668 |
| 16 mm | #5 | 1.58 | 1.043 |
| 19 mm | #6 | 2.23 | 1.502 |
| 25 mm | #8 | 3.85 | 2.670 |
Frequently asked questions
How do you calculate rebar weight?
Multiply the length by the bar's unit weight. For metric bars, weight (kg/m) = diameter in mm squared x 0.006165. A #4 (13 mm) bar weighs about 0.668 lb/ft.
What does rebar size #4 mean?
US rebar numbers give the diameter in eighths of an inch, so #4 is 4/8 = 1/2 inch (about 13 mm) and #5 is 5/8 inch (about 16 mm).
How much does a 16 mm rebar weigh?
A 16 mm (US #5) reinforcing bar weighs about 1.58 kg per metre, or 1.043 lb per foot.
Is rebar weight the same as plain round bar?
The nominal weight is calculated the same way from the effective diameter. The ribs on rebar are included in the standard nominal weight figures.
Steel Rebar Weight Calculator
Calculate the weight of steel rebars based on diameter, length and material type.
How to use this calculator:
- Select the rebar diameter from standard sizes (in mm)
- Enter the length of the rebar in meters or feet
- Select the material type from the dropdown menu
- Enter the quantity of rebars (default is 1)
- Click "Calculate Weight" to get the results
This calculator provides the weight of steel rebars based on their dimensions and material density. Results are shown in kilograms (kg).
Standard Rebar Sizes Reference
| Metric Size (mm) | US Size | Cross Section (mm²) | Weight (kg/m) |
|---|---|---|---|
| 6 mm | #2 | 28.3 | 0.222 |
| 10 mm | #3 | 78.5 | 0.616 |
| 12 mm | #4 | 113.1 | 0.888 |
| 16 mm | #5 | 201.1 | 1.579 |
| 20 mm | #6 | 314.2 | 2.466 |
| 25 mm | #8 | 490.9 | 3.853 |
| 32 mm | #10 | 804.2 | 6.313 |
| 40 mm | - | 1256.6 | 9.864 |