Rebar Calculator
#3 Reinforcing Bar
ASTM A615 (US customary) reinforcing bar — diameter 9.5 mm (0.375 in), cross-sectional area, mass per metre, and standard spacing options.
Diameter
9.5 mm
Area
0.110 in²
Perimeter
1.18 in
Mass per metre
0.38 lb/ft
Area per foot width at common spacings
For slab or wall reinforcement specified as “#3@ spacing c/c” — the area provided per unit width at each standard centre-to-centre spacing.
| Spacing | As (in²/ft) |
|---|---|
| #3 @ 4in c/c | 0.331 |
| #3 @ 6in c/c | 0.221 |
| #3 @ 8in c/c | 0.166 |
| #3 @ 9in c/c | 0.147 |
| #3 @ 10in c/c | 0.133 |
| #3 @ 12in c/c | 0.110 |
| #3 @ 16in c/c | 0.083 |
Equivalent options at 6in spacing
Every US bar size at the same reference spacing, so you can see at a glance which other size lands near the same area per unit width as #3.
| Bar | As (in²/ft) |
|---|---|
| #3 (this bar) | 0.221 |
| #4 | 0.393 |
| #5 | 0.614 |
| #6 | 0.884 |
| #7 | 1.203 |
| #8 | 1.571 |
| #9 | 1.999 |
| #10 | 2.534 |
| #11 | 3.123 |
| #14 | 4.502 |
| #18 | 8.002 |
Area and mass are computed directly from the nominal diameter (mass assumes standard steel density, 7850 kg/m³) — the same values the Rebar Calculator uses.
Open #3 in the Rebar Calculator →