Rebar is bought and delivered by weight but specified by size and length, so converting between the two is part of every concrete reinforcement take-off. This rebar weight calculator turns a bar size, a length and a quantity into pounds, kilograms and US tons, so you can price the steel, check a delivery ticket or plan how to carry it.
How to use the rebar weight calculator
- Choose the bar size, from #3 to #11.
- Enter the length of each bar. Rebar is commonly cut or delivered in 20 ft sticks, but you can enter any length in feet, inches, yards, meters or centimeters.
- Enter the number of bars.
- Read the weight per foot and in total.
Rebar weight formula
Total weight = weight per foot × length (ft) × number of bars
Here d is the nominal bar diameter in inches and 0.2836 lb/in³ is the density of steel (490 lb per cubic foot). The results match the unit weights in ASTM A615/A615M, the standard specification for deformed and plain carbon-steel bars.
Worked example: ten #4 bars, 20 ft long
- Area of a #4 bar: π ÷ 4 × 0.5² = 0.1963 in².
- Weight per foot: 0.1963 × 12 × 0.2836 = 0.668 lb/ft.
- Per 20 ft bar: 0.668 × 20 = 13.4 lb.
- Ten bars: 133.6 lb (60.6 kg, 0.067 tons).
Rebar size and weight chart
| Bar size | Diameter (in) | Area (in²) | Weight (lb/ft) | Weight (kg/m) | 20 ft bar (lb) |
|---|---|---|---|---|---|
| #3 | 0.375 | 0.110 | 0.376 | 0.559 | 7.5 |
| #4 | 0.500 | 0.196 | 0.668 | 0.994 | 13.4 |
| #5 | 0.625 | 0.307 | 1.044 | 1.554 | 20.9 |
| #6 | 0.750 | 0.442 | 1.503 | 2.237 | 30.1 |
| #7 | 0.875 | 0.601 | 2.046 | 3.045 | 40.9 |
| #8 | 1.000 | 0.785 | 2.673 | 3.978 | 53.5 |
| #9 | 1.128 | 0.999 | 3.401 | 5.061 | 68.0 |
| #10 | 1.270 | 1.267 | 4.311 | 6.416 | 86.2 |
| #11 | 1.410 | 1.561 | 5.314 | 7.908 | 106.3 |
Estimating a delivery
Steel yards quote by the hundredweight (cwt, 100 lb) or by the ton, and trucks have weight limits. Total your bars by size, convert each to pounds with this calculator, and add 3% to 5% for cutting waste and the odd bent bar. A pickup bed can carry a few hundred pounds of 20 ft bar safely, but long bars must be tied down and flagged where they overhang.
Notes on rebar
- Grade. Most residential and light commercial work uses Grade 60 (60,000 psi yield) bar. The grade does not change the weight.
- Standard lengths. 20 ft and 40 ft bars are common stock lengths; shorter or bent bars are cut and fabricated to order.
- Waste and laps. Splices overlap the bars, so add the lap length. The Rebar Material Calculator includes laps for slab grids.
- Tie wire and chairs are bought separately and are not included.
Heading for wire mesh instead? See the Concrete Reinforcing Mesh Calculator. To order the concrete itself, use the Concrete Calculator or Concrete Footing Calculator.
Frequently asked questions
How much does #4 rebar weigh?
#4 rebar (1/2 inch) weighs 0.668 pounds per foot, so a 20 foot stick weighs about 13.4 lb, or 6.06 kg.
How is rebar weight calculated?
Multiply the cross-sectional area of the bar by its length and by the density of steel (about 490 lb per cubic foot). For #8 bar: 0.785 in² × 12 in × 0.2836 lb/in³ = 2.67 lb per foot.
What does the number in the rebar size mean?
In US bar designations #3 to #8 give the bar’s nominal diameter in eighths of an inch: #4 is 4/8 = 1/2 inch, #8 is 8/8 = 1 inch. Larger sizes #9, #10 and #11 have special diameters set to match the area of old square bars.
How many pounds of rebar are in a ton?
A US ton is 2,000 pounds, which is about 2,994 feet of #4 bar or about 749 feet of #8 bar.
Is the weight the same for all grades?
Yes. Grade 40, 60 and 75 differ in strength, not in size or weight. Epoxy coating and ties add a small extra weight not included here.