Rebar Cutting List Calculator: Bar Bending Schedule and Weights
Field note: this tool runs entirely in your browser. Load the page before you head out and it keeps working with no signal, and Print or save PDF gives you a clean copy for the truck.
Rebar Cutting List Calculator: Bar Bending Schedule and Weights
Marks in, cutting list out: geometric bend deductions, weights computed from bar diameter, totals per mark, and a first fit plan showing how many stock bars to order.
| Mark | Size | Leg A, in | Leg B, in | Leg C, in | 90 deg bends | Pieces |
|---|---|---|---|---|---|---|
Leg dimensions are outside to outside, the way bars are measured on a schedule. The bend deduction is computed from geometry at your chosen bend radius, and bar weight comes from diameter and steel density rather than a lookup. Detailing standards vary; when your project standard specifies its own deductions and hook lengths, those govern.
From drawings to a cutting list
A bar bending schedule turns reinforcing details into something a shop can cut: every mark with its size, its cut length, how many pieces, and the total weight. The step people get wrong is the bend. Legs on a schedule are measured outside to outside, so a bar bent to 90 degrees is shorter than the sum of its legs; the corner material is shared between the two legs. This tool deducts for that from geometry rather than a rule of thumb.
Where the deduction comes from
Bend a bar around an inside radius of three bar diameters, the common minimum for smaller sizes, and follow the centreline: the arc through the corner replaces the two straight tips that the outside dimensions counted twice. Work the geometry and the deduction lands at almost exactly 2.5 bar diameters per 90 degree bend. For a No. 4 bar that is 1.25 in, so a bar with 24 and 12 in legs cuts at 34.75 in, not 36. Small per bar, but across a few hundred bars it is the difference between a list that fits the stock and one that does not.
Weight needs no lookup table either. A No. 4 bar is half an inch in nominal diameter; take that circular area, multiply by the density of steel at 490 pcf, and you get 0.668 lb per ft, matching the published figure because that is where the published figure came from. Every size in the tool is computed the same way.
The stock plan
The last table fits your cut pieces onto stock bars using a first fit decreasing pass, longest pieces placed first. Ten pieces at 8 ft pack two per 20 ft stock bar, so five stock bars with a 4 ft offcut from each. The plan gives you the bar count to order per size and shows the offcut total, which is your cue to try a different stock length before ordering. It is a good packing, not always the provably perfect one, and it does not account for cutting kerf, which matters for saw cut bars at tight tolerances.
One scope note: this schedules straight legs and 90 degree bends, the bulk of everyday detailing. Standard hooks, 135 degree stirrup bends and project specific deduction rules come from your detailing standard, and when the drawings specify their own numbers, the drawings win.