# How do you make a bar bending schedule?

> A bar bending schedule is the breakdown of all the reinforcing steel bars in a project: type, diameter, length, bends, laps, hooks and weight, so you know how much steel to buy and what it costs. Doing it by hand from the plans is slow and error-prone; with Ironbid.ai the AI generates it automatically from the structural PDF plan.

The bar bending schedule is the document that details, bar by bar, all the reinforcing steel of an element or a project: the mark, the diameter, the cut length, the shape with its bends, the laps, the hooks and the resulting weight. It is the basis for knowing how much steel to buy, how to cut and bend it, and what it costs.

To build it by hand you take each structural element from the plan (footings, columns, beams, slabs, walls), identify the bars by diameter, calculate the development length accounting for bends and hooks, add the laps, and then convert to weight. The weight is obtained by multiplying the total length of each diameter by its weight per meter (which depends on the diameter, using the steel density of 7850 kg/m³). Adding up all the diameters gives you the total weight and the tonnage.

The typical mistakes when doing it by hand are getting the lap lengths wrong, forgetting hooks and bends, confusing diameters, and not accounting for waste properly. Any of them changes the tonnage and therefore the estimate.

With Ironbid.ai the process is automated: you upload the structural PDF plan and the AI detects the bars by diameter and calculates lengths, bends, laps and hooks, delivering the breakdown ready. From that schedule you get the weight per diameter, the tonnage and the steel unit price per kilo fabricated and placed directly. Even so, it is worth reviewing the automatic breakdown on the critical elements, because the tool speeds up the calculation but the technical validation belongs to the estimator or rebar detailer.

## Related questions

### What data does a bar bending schedule contain?

The bar mark, diameter, cut length, shape with its bends, laps, hooks and weight. From that you calculate how much steel to buy and the project tonnage.

### How is the steel weight calculated in the schedule?

You multiply the total length of each diameter by its weight per meter (which depends on the diameter, using the steel density of 7850 kg/m³) and add up all the diameters to get the total weight and tonnage.

### Can the bar bending schedule be generated automatically?

Yes. Ironbid.ai generates the bar bending schedule from the structural PDF plan: it detects the bars by diameter and calculates lengths, bends, laps and hooks, and from that derives the weight and the unit price per kilo.

**Tags:** ironbid, bar bending schedule, rebar schedule, steel takeoff, reinforcing steel, rebar, steel estimating

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