How much does #5 rebar weigh per foot?

1.043 lb/ft, or 1.552 kg/m. The bar is 0.625 in in diameter with a cross-sectional area of 0.307 in².

How do I calculate rebar weight?

Weight per foot = (π/4) × diameter² × 0.2836 × 12. Multiply by the total length for the job. Doubling the diameter quadruples the weight.

What size is #4 rebar?

#4 rebar is 0.500 in (12.7 mm) in nominal diameter. The bar number is the diameter in eighths of an inch for sizes up to #8.

How many #4 bars are in a ton?

At 0.668 lb/ft, a ton (2,000 lb) is about 2,994 ft of #4 bar — roughly 375 bars at 8 ft, or 250 at 12 ft.

Does rebar weight affect concrete cover?

Indirectly. Cover is specified as a distance from the concrete surface to the bar, so larger bars place their centre further in for the same cover. The governing requirement is in the applicable building code.

Rebar Weight Calculator

Compute the weight of a rebar quantity from bar size and total length, and the number of bars needed for a given weight.

Data verified 2026-09-29 · based on n/a — standard engineering relationships, no single governing revision

Quick Answer

Rebar weight per unit length scales with the square of the diameter. A #5 bar weighs 1.043 lb/ft; a #8 bar, with 1.6 times the diameter, weighs 2.56 times as much at 2.670 lb/ft.

Rebar Weight

Bar diameter (in)

Total length (ft)

The Formulas Used

weight per foot = (π/4) × d² × 0.2836 × 12
Bar number is the diameter in eighths of an inch for #3 through #8: d = number ÷ 8.

Weight Scales with Diameter Squared

Doubling the bar diameter quadruples the weight per unit length, because weight follows the cross-sectional area. That is why the step from #8 to #11 nearly doubles the weight per foot while the diameter rises by only 41%.

Weight is what rebar is bought and priced on, so it is the figure a takeoff needs. Use the rebar size chart for the tabulated values per bar size.

Where the Bar Number Breaks Down

The bar number is the diameter in eighths of an inch only up to #8. Above that the sizes were set separately, so #9 is 1.128 in rather than 1.125, and #14 is 1.693 in rather than 1.75. The calculator above uses the actual diameter, so it stays correct across the whole range.

Frequently Asked Questions

How much does #5 rebar weigh per foot?: 1.043 lb/ft, or 1.552 kg/m. The bar is 0.625 in in diameter with a cross-sectional area of 0.307 in².
How do I calculate rebar weight?: Weight per foot = (π/4) × diameter² × 0.2836 × 12. Multiply by the total length for the job. Doubling the diameter quadruples the weight.
What size is #4 rebar?: #4 rebar is 0.500 in (12.7 mm) in nominal diameter. The bar number is the diameter in eighths of an inch for sizes up to #8.
How many #4 bars are in a ton?: At 0.668 lb/ft, a ton (2,000 lb) is about 2,994 ft of #4 bar — roughly 375 bars at 8 ft, or 250 at 12 ft.
Does rebar weight affect concrete cover?: Indirectly. Cover is specified as a distance from the concrete surface to the bar, so larger bars place their centre further in for the same cover. The governing requirement is in the applicable building code.

Value Sources

Each data column on this page is tied to the source it came from. The numbers in square brackets correspond to the table headers above.

#	Source	Type	Revision / method
[1]	ASME B1.1 — Unified Inch Screw Threads	standard	ASME B1.1-2019 — source
[2]	ASTM A615 — Deformed steel bars for concrete reinforcement	standard	ASTM A615/A615M-20 — source
[3]	ASTM E140 — Hardness Conversion Tables	standard	ASTM E140-12b — source
[4]	Values computed in your browser	derived	Evaluated locally from the formulas shown on the page. No data leaves the device.
[5]	ISO 4287 — Surface texture: Profile method	standard	ISO 4287:1997 — source
[6]	ISO 68-1 — Basic profile	standard	ISO 68-1:2023 — source
[7]	NFPA 70 NEC Table 310.16	standard	NEC 2023 (NFPA 70-2023) — source

Data Sources

Standard	Revision	What it covers on this page
Formulas as shown on this page	n/a — standard engineering relationships, no single governing revision	every value this calculator produces

Cross-checked against:

Formulas verified against the corresponding reference chart on this site, so the calculator and the published tables agree

Derived values — the following values on this page are calculated, not taken directly from the standard:

Value	How it is derived
All outputs	Computed in the browser from the formulas above. No data leaves the device.

Outputs are computed from the formulas shown. Verify against the governing standard for design or acceptance work.

Accuracy and use. The values on this page are compiled from the published standards and cross-checked sources listed above. Where values are derived, the derivation is stated. No warranty, express or implied, is made as to the accuracy or completeness of this information, and no liability is accepted for any loss or damage arising from its use. Engineering reference data is provided for guidance in preliminary work — before a value is used for design, fabrication or acceptance testing, verify it against the current revision of the governing standard and against your own inspection. The user assumes all risk and responsibility in connection with the use of this information.

Cite This Page

Every value on this page is traceable to the sources listed above. If you use the data in a document, paper or report, cite it as:

Plain text

Engineering Reference. "Rebar Weight Calculator." https://refmanual.com/calculators/rebar-weight/ (accessed 2026-09-29). Data from Formulas as shown on this page, n/a — standard engineering relationships, no single governing revision.

BibTeX

@misc{rebar-weight,
  title        = {Rebar Weight Calculator},
  author       = {{Engineering Reference}},
  howpublished = {\url{https://refmanual.com/calculators/rebar-weight/}},
  note         = {Accessed: 2026-09-29},
  source       = {Formulas as shown on this page, n/a — standard engineering relationships, no single governing revision}
}

RIS (EndNote, Zotero, Mendeley)

TY  - ELEC
TI  - Rebar Weight Calculator
AU  - Engineering Reference
PB  - Engineering Reference
UR  - https://refmanual.com/calculators/rebar-weight/
PY  - 2026
DA  - 2026-09-29
N1  - Source: Formulas as shown on this page, n/a — standard engineering relationships, no single governing revision
ER  -

Each row in the tables above also has a permanent link — hover a row and use the # link to cite a single value rather than the whole page.