25 mm rebar weight
3.850 kg/m · 2.587 lb/ft
25 mm rebar has a nominal diameter of 25 mm and a cross-sectional area of 491 mm².
25 mm rebar weight calculator
Weight of standard bar lengths
| Bars | 6 m (kg) | 12 m (kg) |
|---|---|---|
| 1 | 23.1 | 46.2 |
| 10 | 231.0 | 462.0 |
| 50 | 1,155.0 | 2,310.0 |
| 100 | 2,310.0 | 4,620.0 |
Bars per tonne
| Bar length | Bars per tonne |
|---|---|
| 6 m | 43.3 |
| 9 m | 28.9 |
| 12 m | 21.6 |
One tonne of 25 mm rebar is 260 m per tonne. Use this to turn a weight on a delivery note into a bar count.
How the weight is calculated
Area = π ÷ 4 × 25² = 490.9 mm². Weight per metre = area × 7850 kg/m³ = 490.9 × 10⁻⁶ m² × 7850 = 3.853 kg/m. The d² ÷ 162 rule gives 625 ÷ 162 = 3.858 kg/m.
Deformed bars and TMT bars are sold by nominal diameter and nominal mass; the ribs are already allowed for, and standards accept a small mass tolerance per bar. See the rebar weight formula guide.
25 mm rebar per square metre of slab
Weight of 25 mm rebar in a slab or wall for common spacings, for one layer in one direction and for bars both ways. Add laps, hooks and chairs on top.
| Spacing (centres) | One direction (kg/m²) | Both directions (kg/m²) |
|---|---|---|
| 100 mm | 38.50 | 77.00 |
| 125 mm | 30.80 | 61.60 |
| 150 mm | 25.67 | 51.33 |
| 200 mm | 19.25 | 38.50 |
| 250 mm | 15.40 | 30.80 |
| 300 mm | 12.83 | 25.67 |
Compared with nearby sizes
| Bar | kg/m | lb/ft | vs this bar |
|---|---|---|---|
| 16 mm rebar | 1.580 | 1.062 | −59 % |
| 20 mm rebar | 2.470 | 1.660 | −36 % |
| 25 mm rebar | 3.850 | 2.587 | — |
| 28 mm rebar | 4.830 | 3.246 | +25 % |
| 32 mm rebar | 6.310 | 4.240 | +64 % |
Bars of this size are typical main reinforcement for beams, columns, footings and retaining walls. The nearest US bar is #8 rebar (25.4 mm, 3.973 kg/m).
Frequently asked questions
What is the weight of 25 mm rebar per metre?
25 mm rebar weighs 3.850 kg/m (2.587 lb/ft). By the rule of thumb d squared over 162: 25 x 25 / 162 = 3.858 kg/m.
How much does a 12 m bar of 25 mm rebar weigh?
46.20 kg (3.850 kg/m × 12 m). A 6 m bar weighs 23.10 kg.
How many 12 m bars of 25 mm rebar are in a tonne?
About 21.6 bars, or 260 m per tonne.
What is the US equivalent of 25 mm rebar?
The nearest US bar is #8 rebar (25.4 mm, 3.973 kg/m). Check the steel area in the design before substituting one for the other.
How is the weight of 25 mm rebar calculated?
Area = π ÷ 4 × 25² = 490.9 mm². Weight per metre = area × 7850 kg/m³ = 490.9 × 10⁻⁶ m² × 7850 = 3.853 kg/m. The d² ÷ 162 rule gives 625 ÷ 162 = 3.858 kg/m.
How much 25 mm rebar is needed per square metre at 150 mm spacing?
One layer at 150 mm centres needs 25.67 kg/m² in one direction, 51.33 kg/m² for bars both ways, plus laps.
Other bar sizes
6 mm rebar · 8 mm rebar · 10 mm rebar · 12 mm rebar · 14 mm rebar · 16 mm rebar · 20 mm rebar · 28 mm rebar · 32 mm rebar · 40 mm rebar · 50 mm rebar
Full rebar weight chart · Steel weight calculator
Data adapted from Wikipedia, "Rebar" (CC BY-SA 4.0).