Bar Bending Schedule Software
// Reinforcement Estimation & Cutting Optimiser
A professional BBS tool for infrastructure engineers. Build detailed reinforcement schedules, auto-calculate bar weights, and minimise steel waste with first-fit decreasing cutting-stock optimisation.
Features
Auto-Calculations
Unit weight, bar length, total bars, and total weight — all derived automatically from your inputs.
35 BS 8666 Shapes
Straight, L-bars, U-bars, links, cranks, circular bars and helicals by shape code, plus custom shapes up to 6 segments — each with an SVG preview.
Cutting Optimisation
First-Fit Decreasing bin-packing per diameter. Offcuts ≥ 500 mm reused. Utilisation % visualised.
Excel & JSON Export
Download your full BBS as a formatted Excel workbook or portable JSON for re-import.
Cloud Save
Save unlimited projects to your account. Organised by client and project name.
Print Ready
A4-friendly print stylesheet covering the full BBS table and cutting plan.
What is a bar bending schedule?
A bar bending schedule (BBS) lists every reinforcement bar in a structural member — bar mark, diameter, BS 8666 shape code, segment dimensions, cut length, number of bars and total weight. The fabricator cuts and bends from it, the site team checks deliveries against it, and the quantity surveyor prices and orders steel from its weight summary.
Done in a spreadsheet, a BBS is slow to build and easy to get wrong: a missed bend deduction or a wrong bar count multiplies through every row. This tool computes cut lengths, bend deductions, bar counts and weights as you type, and checks bends against BS 8666 minimum former radii for the steel grade you choose (B500B, B500C or Fe500).
Rebar weight per metre
Unit weight is the bar diameter in millimetres squared, divided by 162.2 — which follows from steel at 7,850 kg/m³. These are the figures the tool uses for standard diameters:
| Diameter (mm) | Unit weight (kg/m) | 12 m bar (kg) |
|---|---|---|
| ø8 | 0.395 | 4.74 |
| ø10 | 0.617 | 7.40 |
| ø12 | 0.888 | 10.66 |
| ø14 | 1.208 | 14.50 |
| ø16 | 1.578 | 18.94 |
| ø20 | 2.466 | 29.59 |
| ø25 | 3.853 | 46.24 |
| ø32 | 6.313 | 75.76 |
Worked example: 40 bars of ø16 cut to 6.2 m weigh 1.578 × 6.2 × 40 = 391.3 kg.
How the cutting plan saves steel
Bars are bought in stock lengths (12 m by default — you can change it). For each diameter the tool sorts the required cut lengths longest first and packs them onto stock bars using first-fit decreasing. Offcuts of 500 mm or more go back into the pool and are used for shorter bars; anything shorter is counted as scrap, and the utilisation for every diameter is shown.
Bars longer than one stock length can be split with laps. The lap length is a multiple of the bar diameter (50 × ø by default, adjustable, with a recommendation based on the concrete grade).
How it works
- Add each member (footing, beam, slab, column) and its bars: mark, diameter, shape code and dimensions.
- Cut lengths, bend deductions, number of bars and weights fill in automatically.
- Run the cutting plan to see stock bars needed, reused offcuts and scrap per diameter.
- Export to Excel, print the schedule and cutting plan, or save the project to your account.
Frequently asked questions
What is a bar bending schedule (BBS)?
A bar bending schedule lists every reinforcement bar in a structure: its bar mark, diameter, shape code, cut length, number of bars and total weight. Fabricators cut and bend from it, and quantity surveyors price and order steel from its weight summary.
How is the weight of a steel bar calculated?
Unit weight in kg per metre is the diameter in millimetres squared divided by 162.2 (from a steel density of 7,850 kg/m³). A 16 mm bar weighs 16² ÷ 162.2 = 1.578 kg/m. Multiply by the cut length in metres and the number of bars to get the total weight.
Which shape codes does the BBS tool support?
35 BS 8666 shape codes, from 00 (straight) and 11 (L-bar) to links, cranked bars, circular bars and helicals, plus your own custom shapes of up to six segments. Bend deductions are applied automatically for each shape.
How does the cutting optimiser reduce steel waste?
For each diameter it packs the required cut lengths onto standard stock bars (12 m by default) using first-fit decreasing. Offcuts of 500 mm or more are kept and reused for shorter bars; anything shorter is counted as scrap, so you see the utilisation for every diameter.
Can I export the schedule?
Yes. Download a formatted Excel workbook with three sheets (project details, the BBS table and a summary by diameter), save a JSON copy to re-import later, or print an A4 version with the cutting plan.
Is there a free trial?
Yes. A new account gets a 14-day trial of the full tool, with projects saved to your account.