Rebar Weight Calculator
Pick the bar size, enter a length and how many bars, and read the weight. Nominal ASTM A615 weights — the same numbers a supplier's ticket uses.
Weight per foot, and per stock length
Every bar size has a nominal weight per foot; the weight of any bar is that number times its length. The columns on the right are the common stock lengths a yard carries.
| Size | lb/ft | kg/m | 20′ bar | 30′ bar | 40′ bar | 60′ bar |
|---|---|---|---|---|---|---|
| #3 | 0.376 | 0.560 | 7.5 | 11.3 | 15.0 | 22.6 |
| #4 | 0.668 | 0.994 | 13.4 | 20.0 | 26.7 | 40.1 |
| #5 | 1.043 | 1.552 | 20.9 | 31.3 | 41.7 | 62.6 |
| #6 | 1.502 | 2.235 | 30.0 | 45.1 | 60.1 | 90.1 |
| #7 | 2.044 | 3.042 | 40.9 | 61.3 | 81.8 | 122.6 |
| #8 | 2.670 | 3.973 | 53.4 | 80.1 | 106.8 | 160.2 |
| #9 | 3.400 | 5.060 | 68.0 | 102.0 | 136.0 | 204.0 |
| #10 | 4.303 | 6.404 | 86.1 | 129.1 | 172.1 | 258.2 |
| #11 | 5.313 | 7.907 | 106.3 | 159.4 | 212.5 | 318.8 |
| #14 | 7.650 | 11.38 | 153.0 | 229.5 | 306.0 | 459.0 |
| #18 | 13.60 | 20.24 | 272.0 | 408.0 | 544.0 | 816.0 |
Diameters, areas and metric names for each size are on the rebar size chart.
How rebar weight is figured
Weight is length times the nominal weight per foot, and nothing else. The per-foot figure comes from the bar's nominal cross-section — steel weighs about 490 lb per cubic foot, so a square inch of bar weighs 3.40 lb per foot — and the deformations do not add to it: the nominal weight is the whole bar, ribs included. A 20′ #4 is 20 × 0.668 = 13.36 lb whether it is plain, epoxy-coated, or galvanized (the coating adds a few percent at most).
For a slab, count the bars from the cut list, not the plan: a run longer than the stock length is spliced, and each splice adds a lap to the steel that has to be bought. A cut list totals the actual pieces.
Ordering by weight
Suppliers quote rebar by the hundredweight (cwt, 100 lb) or the ton (2,000 lb). Divide a job's total pounds by 2,000 for tons: 3,600 lb of #4 is 1.8 tons. Most yards sell full stock lengths, so the number of bars to order is the cut list's stick count, and the weight to expect on the invoice is that count times the stock-length weight in the table above.