Home › Resources › Rebar weight chart
Rebar weight chart: kg per metre and metres per tonne.
The mass of a steel reinforcing bar depends only on its diameter and length. Use this chart to turn bar lengths from a take-off into kilograms and tonnes.
The formula
Mass per metre in kilograms is the bar diameter in millimetres squared, divided by 162.2. This comes from the cross-section area of a round bar and the density of steel, 7,850 kg/m³. For example, a 16 mm bar weighs 16 × 16 ÷ 162.2 = 1.578 kg per metre.
Weight per metre and per tonne
| Diameter | kg per metre | kg per 12 m bar | Metres per tonne | 12 m bars per tonne |
|---|---|---|---|---|
| 6 mm | 0.222 | 2.66 | 4,506 | 375.5 |
| 8 mm | 0.395 | 4.73 | 2,534 | 211.2 |
| 10 mm | 0.617 | 7.40 | 1,622 | 135.2 |
| 12 mm | 0.888 | 10.65 | 1,126 | 93.9 |
| 14 mm | 1.208 | 14.50 | 828 | 69.0 |
| 16 mm | 1.578 | 18.94 | 634 | 52.8 |
| 20 mm | 2.466 | 29.59 | 406 | 33.8 |
| 25 mm | 3.853 | 46.24 | 260 | 21.6 |
| 28 mm | 4.834 | 58.00 | 207 | 17.2 |
| 32 mm | 6.313 | 75.76 | 158 | 13.2 |
| 40 mm | 9.864 | 118.37 | 101 | 8.4 |
Worked example
The take-off gives 120 bars of 16 mm, each 12 m long.
Total length: 120 × 12 = 1,440 m.
Mass: 1,440 × 1.578 = 2,273 kg, which is 2.27 tonnes.
Planning figures by member
Before bar bending schedules exist, estimators often price steel as kilograms per cubic metre of concrete. These are the planning figures used in the TapeLine 3D demo. Your own project data should replace them.
| Member | Steel, kg per m³ of concrete |
|---|---|
| Bored piles | 90 |
| Pile caps | 110 |
| Ground beams | 140 |
| Slabs | 95 |
| Columns | 190 |
| Beams | 165 |
To convert: concrete volume in m³ × the figure above ÷ 1,000 = tonnes of steel. Lapping, hooks and wastage add to the net length, so the final figure comes from the bar bending schedule.
Guides by TapeLine, quantity take-off software from Natha & Co, founded by Natha Mohamed M.M.
Try Free Beta Version See the 3D take-off
Keep reading
How to calculate concrete volume and formwork area
Formulas and a worked example for slabs, beams, columns, footings, pile caps and piles.
2 min readStructureHow to calculate blockwork quantities
Blocks per square metre, deducting openings, adding breakage, with a worked wall example.
2 min readBasicsWhat is quantity take-off?
Quantity take-off is measuring the materials and work shown on drawings so they can be priced. The basics, the three kinds of measurement and where software helps.
2 min read