Rebar (reinforcing bar) is steel bar used to reinforce concrete structures. Knowing the weight per linear foot is essential for ordering the right quantity, calculating shipping costs, and ensuring your concrete pour meets structural specifications. This calculator covers all standard ASTM A615 rebar sizes from #3 through #18 in both imperial (lb/ft) and metric (kg/m) units.
Last updated: June 2026 — Weights per ASTM A615 / A706 standard specifications for carbon-steel reinforcing bars.
Rebar Weight Calculator
Rebar Weight Chart — All Standard Sizes Per Linear Foot
Weights per ASTM A615 Grade 60 carbon-steel rebar. All values are nominal — actual weight may vary ±2% depending on mill tolerances and rib pattern.
| Bar Size | Diameter (in) | Weight (lb/ft) | Weight (kg/m) | 20-ft Stick (lbs) | LF Per Ton | Typical Use |
|---|---|---|---|---|---|---|
| #3 | 0.375 | 0.376 | 0.561 | 7.52 | 5,319 | Sidewalk mesh, stirrups, ties |
| #4 | 0.500 | 0.668 | 0.996 | 13.36 | 2,994 | Residential slabs, driveways |
| #5 | 0.625 | 1.043 | 1.556 | 20.86 | 1,918 | Foundation walls, retaining walls |
| #6 | 0.750 | 1.502 | 2.240 | 30.04 | 1,332 | Beams, columns, heavy slabs |
| #7 | 0.875 | 2.044 | 3.049 | 40.88 | 978 | Structural beams, bridge decks |
| #8 | 1.000 | 2.670 | 3.982 | 53.40 | 749 | Major beams, commercial slabs |
| #9 | 1.128 | 3.400 | 5.071 | 68.00 | 588 | High-rise columns, piers |
| #10 | 1.270 | 4.303 | 6.418 | 86.06 | 465 | Heavy commercial, bridge piers |
| #11 | 1.410 | 5.313 | 7.924 | 106.26 | 376 | Industrial, caissons, dams |
| #14 | 1.693 | 7.650 | 11.410 | 153.00 | 261 | Major infrastructure |
| #18 | 2.257 | 13.600 | 20.284 | 272.00 | 147 | Nuclear plants, mega-structures |
Rebar sizes #3 through #11 are available in 20-foot and 40-foot lengths at most suppliers. #14 and #18 are special-order for large commercial projects. The bar number equals the nominal diameter in eighths of an inch — #4 = 4/8" = 1/2". Weight per foot follows: Weight (lb/ft) = (bar number)² × 0.668 / 16. For metric: Weight (kg/m) = (diameter in mm)² / 162.
How to Calculate Rebar Weight — Formula and Worked Examples
The standard formula for rebar weight per linear foot in imperial units is:
Where d is the nominal diameter in inches. The constant 0.668 comes from the density of steel (490 lb/ft³) multiplied by the cross-sectional area of a 1-inch diameter round bar divided by 144 square inches per square foot.
Example 1: Weight of #5 Rebar
#5 rebar has a nominal diameter of 5/8 inch = 0.625 inches. Weight per foot = 0.625² × 0.668 = 0.3906 × 0.668 = 1.043 lb/ft. A standard 20-foot stick weighs 1.043 × 20 = 20.86 lbs.
Example 2: Total Weight for a Project
A concrete driveway requires 60 pieces of #4 rebar, each 12 feet long. Weight per piece = 0.668 × 12 = 8.016 lbs. Total weight = 60 × 8.016 = 481 lbs. Add 5% for overlap and waste = 505 lbs to order.
Example 3: How Many Linear Feet from a Ton?
You need 2,000 lbs of #5 rebar. Weight per foot is 1.043 lb/ft. Linear feet = 2,000 / 1.043 = 1,918 linear feet. At standard 20-foot lengths, that's approximately 96 sticks (1,918 / 20 = 95.9, round up to 96).
Rebar Size Selection Guide — Which Size for Your Project?
Residential Concrete Work (#3–#5)
For residential projects like driveways, patios, sidewalks, and garage slabs, #3 and #4 rebar is standard. Use #4 rebar spaced 18–24 inches on-center in a grid pattern for 4-inch-thick slabs. For thicker slabs (6 inches+) or areas with vehicle traffic, upgrade to #5 rebar or reduce spacing to 12–16 inches. Always consult your local building code for minimum rebar size and spacing requirements.
Foundation Walls & Retaining Walls (#4–#7)
Foundation walls use #4 or #5 vertical rebar at 24–48 inches on-center, with #4 horizontal bars at similar spacing. Retaining walls over 4 feet tall require #5 or #6 bars — the taller the wall and the heavier the retained soil, the larger the bar diameter needed. Always have retaining wall rebar specified by a structural engineer; the consequences of getting it wrong include wall collapse.
Beams & Columns (#6–#11)
Structural concrete beams and columns require larger rebar — typically #6 through #8 for residential and #9 through #11 for commercial. Beam rebar is placed in the bottom third of the beam (tension zone) with #3 or #4 stirrups (ties) wrapped around the main bars every 6–12 inches. Column rebar is vertical with spiral or tie confinement. This is always engineer-specified work — never guess beam or column rebar sizes.
Rebar Weight vs Shipping Cost
Rebar is heavy — a bundle of 100 sticks of #5 rebar (20-foot lengths) weighs approximately 2,086 lbs. This exceeds the capacity of most pickup trucks (typical payload: 1,500–2,000 lbs) and requires either multiple trips or delivery by flatbed truck. Always calculate total weight before arranging transport. Most steel suppliers charge $75–200 for local delivery depending on distance and order size. For large orders, delivery is often free or included.