BS 4449 Rebar Weight Chart (kg/m)
- Bar sizes
- 10
- Range
- 6 mm–50 mm
- kg/m, d in mm
- d² / 162
- Used in
- UK and Gulf
BS 4449 bar sizes and weights
| Bar size | Diameter (mm) | Area (mm²) | Mass (kg/m) | Metres per tonne |
|---|---|---|---|---|
| 6 mm | 6 | 28.3 | 0.222 | 4,505 |
| 8 mm | 8 | 50.3 | 0.395 | 2,534 |
| 10 mm | 10 | 78.5 | 0.617 | 1,622 |
| 12 mm | 12 | 113.1 | 0.888 | 1,126 |
| 16 mm | 16 | 201.1 | 1.578 | 634 |
| 20 mm | 20 | 314.2 | 2.466 | 405 |
| 25 mm | 25 | 490.9 | 3.853 | 260 |
| 32 mm | 32 | 804.2 | 6.313 | 158 |
| 40 mm | 40 | 1,256.6 | 9.865 | 101 |
| 50 mm | 50 | 1,963.5 | 15.413 | 65 |
Nominal masses calculated from each bar's nominal diameter at 7,850 kg/m³. Printed tables can differ in the third decimal place through rounding, and delivered bars vary within the rolling tolerance BS 4449 allows.
BS 4449 steel weight calculator
Enter each bar size with the number of bars and the length of each. The total updates as you type, with a summary by size.
53.28 kg
= 0.053 tonnes
Nominal mass only. Add laps, hooks and wastage for an order quantity; rolling tolerance means delivered weight can differ slightly from nominal.
How BS 4449 bars are specified
BS 4449 is the British Standard for weldable reinforcing steel bar, coil and decoiled product. It is specified across the UK and on many projects in the Gulf, usually as grade B500B or B500C.
UK and Gulf drawings typically mark bars by type and diameter, such as H12 or H16, with shapes scheduled to BS 8666.
BS 4449 has one strength, a characteristic yield of 500 MPa, in three ductility classes: B500A, B500B and B500C. B500B and B500C are the usual choice for structural work.
To estimate steel, multiply the total length of each bar size by its mass per metre, then add laps, hooks and a wastage allowance before ordering. Masses on a schedule are nominal; the bars delivered can come in slightly over or under.
The same chart for other standards: IS 1786, AS/NZS 4671 and ASTM A615.
Need the full bar bending schedule?
A weight chart gives you the steel for one bar. A schedule needs every bar on the drawings: shapes, cutting lengths, laps and the totals by size. Send the reinforcement drawings and we return the BBS in Excel, checked and signed off by an engineer.