Rebar Size and Weight Chart (US and Metric)
US bars from ASTM A615 and metric bars from EN 10080 and BS 4449 side by side, with steel area at common spacings and quick site tables for slopes and slab concrete.
Standards and method
US bar dimensions are transcribed from ASTM A615 and cross-checked against a second published table; metric masses, areas and the site tables are calculated.
Maintained by Miguel Coelho. Updated . See our editorial policy.
Printable rebar size chart
US #3 to #18 and metric 6 to 50 mm bars: diameter, area, weight per foot and per metre, plus site quick tables. Includes the exact definition, formulas, a worked example and sources. Conversion values are checked against the defining constants, and reference data is cited to its source, before the PDF is published.
Free to print, share and use in teaching materials with attribution (CC BY 4.0).
Also in the Site Engineer Reference Pack, with related sheets in one PDF.
Full rebar size chart
US #3 to #18 and metric 6 to 50 mm bars: diameter, area, weight per foot and per metre, plus site quick tables. These are the same tables as the printable PDF. For: Site and structural engineers, contractors, estimators, steel fixers and students.
- Key relationship
- US bar number = nominal diameter in eighths of an inch (#3 to #8); metric bars are named by diameter in mm
- Formula
- kg/m = d² ÷ 162.2 (d in mm, steel 7,850 kg/m³)
- Reverse
- d (mm) = √(162.2 × kg/m)
- Worked example
- 16 mm bar: 16² ÷ 162.2 = 1.578 kg/m; #5 bar = 1.043 lb/ft
- Rounding
- US values as published in ASTM A615; metric masses to 3 decimals. Order and check steel to the project specification.
US reinforcing bars (ASTM A615)
| Bar | Metric bar | Diameter (in) | Diameter (mm) | Area (in²) | Area (mm²) | lb/ft | kg/m |
|---|---|---|---|---|---|---|---|
| #3 | #10 | 0.375 | 9.5 | 0.11 | 71 | 0.376 | 0.560 |
| #4 | #13 | 0.500 | 12.7 | 0.20 | 129 | 0.668 | 0.994 |
| #5 | #16 | 0.625 | 15.9 | 0.31 | 200 | 1.043 | 1.552 |
| #6 | #19 | 0.750 | 19.0 | 0.44 | 284 | 1.502 | 2.235 |
| #7 | #22 | 0.875 | 22.2 | 0.60 | 387 | 2.044 | 3.042 |
| #8 | #25 | 1.000 | 25.4 | 0.79 | 510 | 2.670 | 3.973 |
| #9 | #29 | 1.128 | 28.7 | 1.00 | 645 | 3.400 | 5.060 |
| #10 | #32 | 1.270 | 32.3 | 1.27 | 819 | 4.303 | 6.404 |
| #11 | #36 | 1.410 | 35.8 | 1.56 | 1,006 | 5.313 | 7.907 |
| #14 | #43 | 1.693 | 43.0 | 2.25 | 1,452 | 7.650 | 11.384 |
| #18 | #57 | 2.257 | 57.3 | 4.00 | 2,581 | 13.600 | 20.239 |
Metric reinforcing bars (EN 10080 / BS 4449)
| Diameter (mm) | Area (mm²) | kg/m | m per tonne | lb/ft | Nearest US bar |
|---|---|---|---|---|---|
| 6 | 28.3 | 0.222 | 4,505.4 | 0.149 | #3 |
| 8 | 50.3 | 0.395 | 2,534.3 | 0.265 | #3 |
| 10 | 78.5 | 0.617 | 1,622.0 | 0.414 | #3 |
| 12 | 113.1 | 0.888 | 1,126.4 | 0.597 | #4 |
| 14 | 153.9 | 1.208 | 827.5 | 0.812 | #4 |
| 16 | 201.1 | 1.578 | 633.6 | 1.061 | #5 |
| 20 | 314.2 | 2.466 | 405.5 | 1.657 | #6 |
| 25 | 490.9 | 3.853 | 259.5 | 2.589 | #8 |
| 28 | 615.8 | 4.834 | 206.9 | 3.248 | #9 |
| 32 | 804.2 | 6.313 | 158.4 | 4.242 | #10 |
| 40 | 1,256.6 | 9.865 | 101.4 | 6.629 | #14 |
| 50 | 1,963.5 | 15.413 | 64.9 | 10.357 | #14 |
Bar area per metre width at common spacings (mm²/m)
Area of steel per metre of slab or wall = bar area × 1000 ÷ spacing (mm).
| Bar (mm) | @100 | @125 | @150 | @175 | @200 | @225 | @250 | @300 |
|---|---|---|---|---|---|---|---|---|
| 8 | 503 | 402 | 335 | 287 | 251 | 223 | 201 | 168 |
| 10 | 785 | 628 | 524 | 449 | 393 | 349 | 314 | 262 |
| 12 | 1,131 | 905 | 754 | 646 | 565 | 503 | 452 | 377 |
| 16 | 2,011 | 1,608 | 1,340 | 1,149 | 1,005 | 894 | 804 | 670 |
| 20 | 3,142 | 2,513 | 2,094 | 1,795 | 1,571 | 1,396 | 1,257 | 1,047 |
| 25 | 4,909 | 3,927 | 3,272 | 2,805 | 2,454 | 2,182 | 1,963 | 1,636 |
Slope: percent, ratio and angle
| Percent | Ratio (1 in …) | Degrees | mm per m |
|---|---|---|---|
| 0.5% | 1 in 200 | 0.29 | 5 |
| 1% | 1 in 100 | 0.57 | 10 |
| 1.5% | 1 in 66.7 | 0.86 | 15 |
| 2% | 1 in 50 | 1.15 | 20 |
| 2.5% | 1 in 40 | 1.43 | 25 |
| 3% | 1 in 33.3 | 1.72 | 30 |
| 4% | 1 in 25 | 2.29 | 40 |
| 5% | 1 in 20 | 2.86 | 50 |
| 6% | 1 in 16.7 | 3.43 | 60 |
| Percent | Ratio (1 in …) | Degrees | mm per m |
|---|---|---|---|
| 8% | 1 in 12.5 | 4.57 | 80 |
| 10% | 1 in 10 | 5.71 | 100 |
| 12.5% | 1 in 8 | 7.13 | 125 |
| 15% | 1 in 6.7 | 8.53 | 150 |
| 20% | 1 in 5 | 11.31 | 200 |
| 25% | 1 in 4 | 14.04 | 250 |
| 33.33% | 1 in 3 | 18.43 | 333 |
| 50% | 1 in 2 | 26.57 | 500 |
| 100% | 1 in 1 | 45.00 | 1,000 |
Concrete volume for slabs
Add a waste allowance (typically 5–10%) when ordering.
| Thickness (mm) | m³ per 10 m² | Thickness (in) | yd³ per 100 ft² |
|---|---|---|---|
| 75 | 0.75 | 3 | 0.93 |
| 100 | 1.00 | 4 | 1.23 |
| 125 | 1.25 | 5 | 1.54 |
| 150 | 1.50 | 6 | 1.85 |
| 175 | 1.75 | 7 | 2.16 |
| 200 | 2.00 | 8 | 2.47 |
| 250 | 2.50 | 10 | 3.09 |
| 300 | 3.00 | 12 | 3.70 |
Sources for this chart
US bar dimensions are transcribed from ASTM A615 and cross-checked against a second published table; metric masses, areas and the site tables are calculated.
- ASTM A615/A615M — Deformed and plain carbon-steel bars for concrete reinforcement: nominal dimensions and masses
- EN 10080 and BS 4449 — Steel for the reinforcement of concrete: preferred metric diameters (7,850 kg/m³)
Related Converters & Charts
Rebar Size and Weight Chart (US and Metric) FAQs
Common questions about the rebar size chart.
What is the diameter of #4 rebar?
#4 rebar is 0.500 in (12.7 mm) in diameter, with an area of 0.20 in² and a weight of 0.668 lb/ft (0.994 kg/m). Its soft-metric name is #13.
How much does 16 mm rebar weigh per metre?
Mass = d² ÷ 162.2 = 16² ÷ 162.2 = 1.578 kg/m, so a 12 m bar weighs about 18.9 kg.
What does the rebar number mean?
For US bars #3 to #8 the number is the diameter in eighths of an inch: #5 is 5/8 in. Larger bars are close to, but not exactly, that rule.
Can I download this chart as a PDF, CSV, or JSON?
Yes. Use the Download A4 PDF or US Letter PDF buttons for a printable version, or download the same tables as CSV or JSON from the links on this page.