U.S. Rebar Size, Diameter & Weight Chart
Common U.S. reinforcing-bar size numbers with nominal diameter and approximate unit weight.
Editorial review: 2026-09-29 · How we review technical content
Key takeaways
- Bar numbers for #3 through #8 correspond approximately to diameter in eighths of an inch; larger sizes use standardized nominal dimensions.
- Bar grade, coating, deformation requirements, bend details, spacing, cover, development, and lap requirements are separate design/specification issues.
| Bar size | Nominal diameter | Approx. weight |
|---|---|---|
| #3 | 0.375 in. | 0.376 lb/ft |
| #4 | 0.500 in. | 0.668 lb/ft |
| #5 | 0.625 in. | 1.043 lb/ft |
| #6 | 0.750 in. | 1.502 lb/ft |
| #7 | 0.875 in. | 2.044 lb/ft |
| #8 | 1.000 in. | 2.670 lb/ft |
| #9 | 1.128 in. | 3.400 lb/ft |
| #10 | 1.270 in. | 4.303 lb/ft |
| #11 | 1.410 in. | 5.313 lb/ft |
How to read this table
Bar numbers for #3 through #8 correspond approximately to diameter in eighths of an inch; larger sizes use standardized nominal dimensions.
Where it is useful
Use the table for estimating weight, checking a delivery, or translating bar callouts when preparing a takeoff.
Limitations
Bar grade, coating, deformation requirements, bend details, spacing, cover, development, and lap requirements are separate design/specification issues.
How to apply this reference
Bar number, nominal diameter and weight are useful for takeoff and handling, but placement still follows the reinforcing drawings.
Do not infer required spacing, lap or development length from a size/weight table.
References & further reading
- American Concrete Institute — Primary industry source for concrete codes, specifications, guides, and educational resources.
- ASTM Cement and Concrete Standards — Primary catalog for current concrete test methods and material standards.
- ACI SPEC-301-20 — Specifications for Concrete Construction — Reference specification used when incorporated into project specifications.