Bar number
For US reinforcing bars #3 through #8, the bar number is approximately the nominal diameter in eighths of an inch.
Structural property table
Rebar Size Chart
Reference US reinforcing bar numbers, nominal diameters, cross-sectional areas, and nominal weights for concrete design and detailing checks.
US reinforcing bars
US rebar sizes
| Bar Size | Nominal Diameter (in) | Diameter (mm) | Area (in^2) | Area (mm^2) | Weight (lb/ft) |
|---|---|---|---|---|---|
| #3 | 0.375 | 9.5 | 0.11 | 71 | 0.376 |
| #4 | 0.500 | 12.7 | 0.20 | 129 | 0.668 |
| #5 | 0.625 | 15.9 | 0.31 | 200 | 1.043 |
| #6 | 0.750 | 19.1 | 0.44 | 284 | 1.502 |
| #7 | 0.875 | 22.2 | 0.60 | 387 | 2.044 |
| #8 | 1.000 | 25.4 | 0.79 | 510 | 2.670 |
| #9 | 1.128 | 28.7 | 1.00 | 645 | 3.400 |
| #10 | 1.270 | 32.3 | 1.27 | 819 | 4.303 |
| #11 | 1.410 | 35.8 | 1.56 | 1006 | 5.313 |
| #14 | 1.693 | 43.0 | 2.25 | 1452 | 7.650 |
| #18 | 2.257 | 57.3 | 4.00 | 2581 | 13.600 |
Reference notes
Using rebar size data
Area
Cross-sectional area is commonly used in reinforced concrete design checks, spacing calculations, and steel ratio estimates.
Weight
Nominal weight per foot is useful for takeoffs, estimating, handling, and material planning.
Design requirements
Use the project specification and applicable concrete design code for grade, development length, spacing, lap length, and cover requirements.