US and metric bar diameter, area and weight
| Bar | Metric name | Diameter (in) | Diameter (mm) | Area (in²) | Area (mm²) | Weight (lb/ft) | Mass (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 |
Nominal dimensions per ASTM A615/A615M (ASTM A706 uses the same sizes). Metric columns are converted from the inch-pound values.
| Bar | Diameter (mm) | Area (mm²) | Mass (kg/m) | Diameter (in) | Area (in²) | Weight (lb/ft) |
|---|---|---|---|---|---|---|
| 10M | 11.3 | 100 | 0.785 | 0.445 | 0.16 | 0.527 |
| 15M | 16.0 | 200 | 1.570 | 0.630 | 0.31 | 1.055 |
| 20M | 19.5 | 300 | 2.355 | 0.768 | 0.47 | 1.582 |
| 25M | 25.2 | 500 | 3.925 | 0.992 | 0.78 | 2.637 |
| 30M | 29.9 | 700 | 5.495 | 1.177 | 1.09 | 3.692 |
| 35M | 35.7 | 1,000 | 7.850 | 1.406 | 1.55 | 5.275 |
| 45M | 43.7 | 1,500 | 11.775 | 1.720 | 2.33 | 7.912 |
| 55M | 56.4 | 2,500 | 19.625 | 2.220 | 3.88 | 13.187 |
Nominal dimensions per CSA G30.18 (Canada). To count bars and weight for a slab or wall, use the rebar calculator.
For #3 through #8, the bar number is the nominal diameter in eighths of an inch: #4 is 4/8 = 0.5 in. Sizes #9 and up keep the same area as the old square bars, so the rule no longer holds exactly.
Those are the ASTM A615M soft metric names for #3, #4 and #5. The number is the diameter rounded to millimeters. The bar is physically the same.
They are different bars. 15M (CSA G30.18) is 16.0 mm with 200 mm² of area. A #5 is 15.9 mm with 0.31 in² (200 mm²). They are close but not interchangeable on drawings.
20 × 0.668 = 13.4 lb. A 20 ft #5 weighs 20 × 1.043 = 20.9 lb.