# Bar Bending Schedule Calculator

> Free BBS calculator for bar bending schedules, rebar cutting lengths, stirrups, bend deductions and steel quantity for beams, columns, slabs and footings.

Enter your bar marks, shapes, legs and quantities. Cut lengths, bend allowances and total steel weight are calculated as you type — entirely in your browser.

- **HTML page:** https://siteometry.com/en/tools/bbs
- **Category:** [Steel & Rebar](https://siteometry.com/en/tools/category/steel-rebar)
- **Figures live on the page:** tables, diagrams and worked figures the text refers to ("the table below") are drawn by the page and are not reproduced here. Each section below links to its anchor on the page.
- **Runs in the browser:** Siteometry calculators need no account and send no input anywhere — every number below is computed on the visitor's own device.

## Prepare a schedule in seven steps

1. **Choose units and standard** — Pick metric or imperial units and the reinforcement standard your project specifies.
2. **Add bar marks** — Add a row for each distinct bar mark in the element.
3. **Choose shape and diameter** — Select the bar shape and diameter for the mark.
4. **Enter dimensions, cover and hooks** — Type the scheduled leg lengths, the cover, and the number of end hooks where the shape needs them.
5. **Enter quantity or spacing** — Enter the number of bars directly, or a spacing and span to count them automatically.
6. **Review warnings** — Check any row flagged incomplete or approximate and supply a value the standard does not publish.
7. **Export or print** — Export the schedule to CSV for Excel, or print it as a clean schedule.

_On the page: https://siteometry.com/en/tools/bbs#howto_

## Bar bending schedule guide

The calculator above builds a full bar bending schedule as you type: cut lengths, bend allowances and total steel weight, all worked out in your browser.

The guide below explains what a bar bending schedule is, the formulas behind the numbers, how each supported standard differs, and worked examples you can reproduce by hand.

_On the page: https://siteometry.com/en/tools/bbs#bbs-guide-intro_

## What is a bar bending schedule?

A bar bending schedule (BBS) is a tabular list of every reinforcement bar in a structural element. Each row — a “bar mark” — records the bar's shape, diameter, leg dimensions, number of bars, cutting length and weight.

The schedule does two jobs. It tells the steel fixer or fabricator exactly what to cut and bend, and it tells the estimator how much steel to order and what it weighs. The dimensions come straight from the structural drawings; the schedule turns them into cut bars.

Schedule notation and shape codes vary by country and standard, so the same stirrup can be written differently under IS 2502, BS 8666 or ACI. The calculator keeps the maths consistent once you pick a standard.

_On the page: https://siteometry.com/en/tools/bbs#what-is-bbs_

## How this calculator works

You enter the bars; the calculator handles the geometry. For each mark you choose a shape and diameter, type the scheduled leg lengths and cover, set how many bars there are, and pick the reinforcement standard. As you type it returns the cutting length per bar, the weight per bar, and totals grouped by diameter.

Outputs can be exported to CSV for Excel or printed as a clean schedule. Rows that depend on a value the standard does not publish are flagged so you can supply or verify it.

Everything is calculated on your device. Nothing you enter is uploaded, and your schedule is saved only in your own browser.

_On the page: https://siteometry.com/en/tools/bbs#how-calculator-works_

## Core BBS formulas

Three formulas drive a schedule: cutting length, steel weight, and bar count. Cutting length is the length of straight bar to cut before bending; it adds hook allowances and subtracts a small deduction at each bend because steel stretches as it is bent.

Hook and bend rules are standard-specific, so the exact numbers below come from the standard you select rather than one universal table. The d²/162 unit-weight figure is a widely used approximation, not a value published by any of these standards — where a standard ships a bar-mass table, the calculator uses that table instead and only falls back to d²/162 for off-table diameters.

_On the page: https://siteometry.com/en/tools/bbs#cutting-length-formulas_

## Stirrups, links, hooks and bend deductions

Stirrups, links and ties are the closed or hooked transverse bars in beams and columns. Their cutting length starts from the outer dimensions, deducts the cover on each face to reach the bar centre-line, adds the hook allowance for the two end hooks, then subtracts the bend deductions at the corners.

Hook length depends on the hook angle (90°, 135° or 180°), the bar diameter and the standard. ACI publishes hook tables by bar size; IS 2502 uses a multiple of the diameter; BS 8666 derives the hook from the bar's end projection and mandrel. There is no single hook or bend-deduction value that is correct for every standard.

That is why the standard you choose changes the result: the active standard's data panel above the schedule controls every hook, bend and rounding rule the calculator applies.

_On the page: https://siteometry.com/en/tools/bbs#stirrups-and-links_

## Standards supported

The calculator ships seven reinforcement presets. Each is built from published values where they exist and from clearly flagged assumptions where a standard does not publish a scheduling figure. The table below summarises what each preset calculates directly and what you should confirm for your own project.

_On the page: https://siteometry.com/en/tools/bbs#standards_

## Worked examples

Each example below reproduces exactly what the calculator returns, so you can check the method by hand. Dimensions are the scheduled (centre-line, cover-adjusted) values, not the out-to-out size.

_On the page: https://siteometry.com/en/tools/bbs#examples_

## BBS for beams, columns, slabs and footings

Beams: schedule the top and bottom main bars, any bent-up or cranked bars, and the stirrups. Take dimensions from the section and elevation, and set the stirrup count from the spacing and span.

Columns: schedule the vertical main bars together with their lap or anchorage lengths, then the lateral ties or links as a tie/stirrup shape, counted from the tie spacing over the column height.

Slabs: mostly straight and cranked bars running in two directions. Use the spacing-and-span count mode to get the number of bars across each direction, and schedule distribution bars the same way.

Footings: schedule the bottom mat in both directions plus any dowels or starter bars, using straight or L-shaped marks counted from the spacing.

In every case the calculator prepares the schedule from dimensions you provide — bar sizes, spacing and cover come from your structural drawings, not from this tool.

_On the page: https://siteometry.com/en/tools/bbs#beam-column-slab-footing_

## Common mistakes to avoid

Mixing standards. Hook and bend rules differ between IS 2502, BS 8666, ACI, Eurocode 2, AS 3600 and CSA. Using one standard's deduction table for another gives the wrong cutting length.

Entering out-to-out dimensions instead of scheduled ones. Stirrup and link dimensions are taken to the bar centre-line after deducting cover, not to the outside face of the steel.

Ignoring cover. Forgetting to deduct cover inflates every stirrup and tie in the schedule.

Treating d²/162 as a published standard value. It is a density-derived approximation; use the standard's bar-mass table where one exists.

Forgetting rounding. Many standards round the final cut length up to a fixed increment (for example 25 mm). Skipping it makes the schedule disagree with the fabricator.

Treating Eurocode 2, AS/NZS or CSA as a full shape-code catalogue. They publish bend and mandrel rules, not a complete BS-8666-style shape library, so confirm shape detailing from your project documents.

_On the page: https://siteometry.com/en/tools/bbs#mistakes_

## Frequently asked questions

Short answers to the questions people most often ask about bar bending schedules and this calculator.

### What is a bar bending schedule (BBS)?

A bar bending schedule is a tabular list of every reinforcement bar in a structural element — its mark, shape, diameter, dimensions, number of bars, cutting length and weight. It tells the fabricator what to cut and bend, and tells the estimator how much steel to order.

### How do you calculate a bar bending schedule?

For each bar mark, take the scheduled dimensions from the drawing, add the hook and bend allowances for the chosen standard, subtract the bend deductions, and round to the standard's increment to get the cutting length. Then multiply unit weight × cutting length × number of bars for the steel weight. This calculator does each step as you type.

### What is cutting length?

Cutting length is the straight length of bar to cut before bending. It is the sum of the bar's straight legs plus hook allowances, minus the bend deductions that account for steel stretching around each bend — so it is longer than the bare dimensions where there are hooks and shorter at bends.

### How do you find the cutting length of a stirrup?

Take the stirrup's outer dimensions, deduct the cover on each face to reach the bar centre-line, add the hook allowance for its two end hooks, then subtract the bend deductions for its corners. The standard you pick sets the hook length and the bend rule.

### How do you calculate rebar weight?

This bar bending schedule already includes bar weight as part of every mark: it multiplies the standard's unit weight (mass per metre) by the cutting length and the number of bars, then totals the steel for you. If you only need bar weights or tonnage and don't need a full schedule, use the dedicated Rebar Weight Calculator tool instead.

### What is bend deduction?

When a bar is bent, the steel stretches, so the cut length is slightly less than the sum of the leg lengths. Bend deduction is that adjustment. It is not a single universal value — it depends on the bar diameter, the bend angle and the standard, which is why the calculator applies the selected standard's rule rather than one fixed table.

### What is hook length or hook allowance?

A hook allowance is the extra bar length added where an end is hooked for anchorage or to close a stirrup. Its size depends on the hook angle (90°, 135° or 180°), the bar diameter and the standard — ACI publishes hook tables by bar size, while IS 2502 uses a multiple of the diameter.

### How do you prepare a BBS for a beam?

List the top and bottom main bars, any bent-up or cranked bars, and the stirrups. Enter each as a bar mark with its shape, take dimensions from the beam section and elevation, and set the stirrup count from the spacing and span. The calculator prepares the schedule; it does not size the reinforcement.

### How do you prepare a BBS for a column?

Schedule the vertical main bars with their lap or anchorage lengths from the drawing, then the lateral ties or links. Use a tie or stirrup shape for the links and set the count from the tie spacing over the column height. Bar sizing comes from the structural design, not this tool.

### How do you prepare a BBS for a slab?

Slabs are mostly straight and cranked bars running in two directions. Enter each layer as a mark, use the spacing-and-span count mode to get the number of bars across the slab, and repeat for the other direction. Distribution bars are scheduled the same way.

### How do you prepare a BBS for a footing?

Schedule the bottom mat in both directions, plus any dowels or starter bars. Use straight or L-shaped marks, set counts from the spacing and the footing dimension, and add the dowel marks separately. Bar size and cover come from your drawing.

### Which standard should I choose?

Pick the standard your project specifies — IS 2502 (India), BS 8666 (UK), ACI / ASTM (US), Eurocode 2 (EU), AS 3600 (Australia and NZ), CSA (Canada) or the editable Generic preset. Hook and bend rules differ between them, so the wrong choice gives the wrong cutting length. Confirm any value flagged as assumed against your project documents.

### Can I export the schedule to Excel?

Yes. Use Export CSV to download the schedule, which opens directly in Excel, Google Sheets or Numbers. You can also use Print schedule to produce a clean PDF or paper copy.

### Is the calculator private?

Yes. Every calculation runs in your browser — nothing you enter is uploaded to a server. Your schedule is saved only in your own browser's local storage, so you can close the tab and return to it later.

_On the page: https://siteometry.com/en/tools/bbs#faq_

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