#8 Rebar — Diameter, Weight & Area
Deformed reinforcing bar per ASTM A615 / A706
#8 rebar (also written No. 8 or number 8 bar) is 1" — 1 inches (25.4 mm) — in nominal diameter; the "8" stands for 8/8 of an inch. It weighs 2.67 pounds per foot (3.973 kg/m) with a nominal cross-section of 0.79 in² (510 mm²). A standard 20 ft bar weighs 53.4 lb, a 40 ft bar 106.8 lb.
These nominal values (per ASTM A615) are what reinforcement schedules, quotes, and delivery tickets use — the deformations are already accounted for in the nominal diameter.
Size & Weight
| Nominal diameter | 1 in (25.4 mm) |
| Nominal area | 0.79 in² (510 mm²) |
| Weight | 2.67 lb/ft (3.973 kg/m) |
Ordering Numbers
| 20 ft bar | 53.4 lb |
| 40 ft bar | 106.8 lb |
| Bars per US ton (20 ft) | 37 |
Frequently Asked Questions
What is the diameter of #8 rebar?
1", i.e. 1 inches or 25.4 mm — bar numbers count eighths of an inch, so #8 is nominally 8/8".
How thick is #8 rebar?
Number 8 bar is 1" thick (25.4 mm). That is the nominal diameter: the ribs are already included, because the nominal size is defined by mass per foot.
How much does #8 rebar weigh per foot?
2.67 lb per foot (3.973 kg/m). A 20 ft bar weighs 53.4 lb; a US ton is about 37 such bars.
What is the area of #8 rebar?
The nominal cross-section of #8 is 0.79 in² (510 mm²) — the value reinforcement schedules use when summing required steel area.
What is the metric equivalent of #8 rebar?
The closest European size is Ø25 (25 mm, 3.85 kg/m, B500 per EN 10080). Matches are approximate — when substituting, match the required steel area, not the bar count.
What grade is #8 rebar?
Grade is independent of size: ASTM A615 Grade 40, 60, or 75 (yield in ksi), with Grade 60 the US default. A706 covers weldable low-alloy bars for seismic work.
Values are entered from the governing standard’s published tables and cross-checked programmatically against its mass and section formulas before publication. Spotted an error? Write to advertising@metalabout.net — verified corrections ship within days. About