Worked example
You need 100 12 mm bars, each 12 m long. One bar weighs 12 × 0.888, or 10.65 kg. 100 bars weigh 1,065.38 kg. That is 1.065 metric tonnes, or 2,348.75 lb. With 5 percent added for laps and cut-offs the order weight is 1,118.65 kg.
Where this bar is used
A 12 mm bar is one of the most used sizes in countries that buy rebar by diameter. Slabs, beams, stirrups and small columns often use it.
In the US, no standard bar is exactly 12 mm. The nearest ASTM bar is M13, the same steel as a US #4, at 12.7 mm. It weighs 0.994 kg/m, about 12 percent more than a 12 mm bar. Do not swap the two without the engineer.
Weight depends on the diameter, not on the steel grade. A 12 mm bar weighs the same in any grade.
12 mm compared with nearby sizes
A 12 mm bar weighs 44 percent more per meter than a 10 mm bar (0.617 kg/m). A 14 mm bar weighs 36 percent more than a 12 mm bar (1.208 kg/m). Weight follows the area of the bar, so it grows with the square of the diameter.