Steel Rebar Weight Calculator
Calculate reinforcing bar weight by metric diameter or US bar number. Enter the bar size, the length and how many bars, and get the total tonnage for your order or bar schedule.
Rebar weight
Nominal weight from dimensions and density. Actual weight varies with mill tolerance and coating — check the mill certificate for critical use.
Rebar unit weights
| Metric | kg/m | US bar | Nominal dia | lb/ft |
|---|---|---|---|---|
| 6 mm | 0.222 | #3 | 9.5 mm | 0.374 |
| 8 mm | 0.395 | #4 | 12.7 mm | 0.668 |
| 10 mm | 0.617 | #5 | 15.9 mm | 1.047 |
| 12 mm | 0.888 | #6 | 19.1 mm | 1.511 |
| 14 mm | 1.208 | #7 | 22.2 mm | 2.042 |
| 16 mm | 1.578 | #8 | 25.4 mm | 2.673 |
| 18 mm | 1.998 | #9 | 28.7 mm | 3.412 |
| 20 mm | 2.466 | #10 | 32.3 mm | 4.322 |
| 22 mm | 2.984 | #11 | 35.8 mm | 5.309 |
| 25 mm | 3.853 | #14 | 43.0 mm | 7.660 |
| 28 mm | 4.834 | #18 | 57.3 mm | 13.602 |
US bar numbers give the diameter in eighths of an inch — a #5 bar is 5/8 inch (about 15.9 mm). The unit weight formula is the same as round bar: kg/m = d² × 0.006165.
Frequently asked questions
How do you calculate rebar weight?
Multiply the bar's unit weight by its length and the number of bars. Unit weight in kg/m equals diameter in mm squared times 0.006165.
What does rebar size #4 mean?
US bar numbers give the nominal diameter in eighths of an inch, so #4 is 4/8 = 1/2 inch, about 12.7 mm.
How much does 12 mm rebar weigh?
About 0.888 kg per metre. A 12 m length weighs roughly 10.7 kg.
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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 |