40 mm rebar weight
9.860 kg/m · 6.626 lb/ft
40 mm rebar has a nominal diameter of 40 mm and a cross-sectional area of 1257 mm².
40 mm rebar weight calculator
Weight of standard bar lengths
| Bars | 6 m (kg) | 12 m (kg) |
|---|---|---|
| 1 | 59.2 | 118.3 |
| 10 | 591.6 | 1,183.2 |
| 50 | 2,958.0 | 5,916.0 |
| 100 | 5,916.0 | 11,832.0 |
Bars per tonne
| Bar length | Bars per tonne |
|---|---|
| 6 m | 16.9 |
| 9 m | 11.3 |
| 12 m | 8.5 |
One tonne of 40 mm rebar is 101 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 × 40² = 1,256.6 mm². Weight per metre = area × 7850 kg/m³ = 1,256.6 × 10⁻⁶ m² × 7850 = 9.865 kg/m. The d² ÷ 162 rule gives 1600 ÷ 162 = 9.877 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.
40 mm rebar per square metre of slab
Weight of 40 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 | 98.60 | 197.20 |
| 125 mm | 78.88 | 157.76 |
| 150 mm | 65.73 | 131.47 |
| 200 mm | 49.30 | 98.60 |
| 250 mm | 39.44 | 78.88 |
| 300 mm | 32.87 | 65.73 |
Compared with nearby sizes
| Bar | kg/m | lb/ft | vs this bar |
|---|---|---|---|
| 28 mm rebar | 4.830 | 3.246 | −51 % |
| 32 mm rebar | 6.310 | 4.240 | −36 % |
| 40 mm rebar | 9.860 | 6.626 | — |
| 50 mm rebar | 15.400 | 10.348 | +56 % |
Bars this heavy are used in heavily loaded columns, transfer beams, piles, bridge decks and large foundations. The nearest US bar is #14 rebar (43 mm, 11.384 kg/m).
Frequently asked questions
What is the weight of 40 mm rebar per metre?
40 mm rebar weighs 9.860 kg/m (6.626 lb/ft). By the rule of thumb d squared over 162: 40 x 40 / 162 = 9.877 kg/m.
How much does a 12 m bar of 40 mm rebar weigh?
118.32 kg (9.860 kg/m × 12 m). A 6 m bar weighs 59.16 kg.
How many 12 m bars of 40 mm rebar are in a tonne?
About 8.5 bars, or 101 m per tonne.
What is the US equivalent of 40 mm rebar?
The nearest US bar is #14 rebar (43 mm, 11.384 kg/m). Check the steel area in the design before substituting one for the other.
How is the weight of 40 mm rebar calculated?
Area = π ÷ 4 × 40² = 1,256.6 mm². Weight per metre = area × 7850 kg/m³ = 1,256.6 × 10⁻⁶ m² × 7850 = 9.865 kg/m. The d² ÷ 162 rule gives 1600 ÷ 162 = 9.877 kg/m.
How much 40 mm rebar is needed per square metre at 150 mm spacing?
One layer at 150 mm centres needs 65.73 kg/m² in one direction, 131.47 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 · 25 mm rebar · 28 mm rebar · 32 mm rebar · 50 mm rebar
Full rebar weight chart · Steel weight calculator
Data adapted from Wikipedia, "Rebar" (CC BY-SA 4.0).