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.
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.
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.
Prepare a schedule in seven steps
- Choose units and standardPick metric or imperial units and the reinforcement standard your project specifies.
- Add bar marksAdd a row for each distinct bar mark in the element.
- Choose shape and diameterSelect the bar shape and diameter for the mark.
- Enter dimensions, cover and hooksType the scheduled leg lengths, the cover, and the number of end hooks where the shape needs them.
- Enter quantity or spacingEnter the number of bars directly, or a spacing and span to count them automatically.
- Review warningsCheck any row flagged incomplete or approximate and supply a value the standard does not publish.
- Export or printExport the schedule to CSV for Excel, or print it as a clean schedule.
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.
The numbers in the schedule come from these formulas.
Cutting length
cutting length = Σ straight legs + Σ hook allowances − Σ bend deductions- Hook allowances and bend deductions are read from the selected standard.
- The final length is rounded up to the standard's increment (for example 25 mm under IS 2502).
Unit weight (mass per metre)
unit weight ≈ d² ÷ 162 (kg/m, d in mm)- d²/162 is a steel-density approximation, not a value published by these standards.
- Where the standard ships a bar-mass table, the calculator uses that table and only falls back to d²/162 for off-table diameters — flagging the row approximate.
Steel weight
weight = unit weight × cutting length × number of bars- Totals are grouped by diameter so you can order steel by size.
Bar count from spacing
number of bars = floor(span ÷ spacing) + 1- Use this when bars are placed at a spacing across a span; otherwise enter the quantity directly.
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.
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.
| Standard | What it calculates from published data | What to verify for your project |
|---|---|---|
| IS 2502 (India) | Hook and bend allowances and the 25 mm cut-length rounding from IS 2502 Table II, for stirrup, hook and cranked shapes. | Bar mass (IS 2502 does not publish it — the calculator uses the d²/162 convention) and the steel-grade factor variant. |
| BS 8666:2020 (UK) | Shape-code geometry — end projection, hook dimension and mandrel — for the standard shape codes, using a published bar-mass table. | The BS 8666 Tables 2–3 numeric values and the final cut-length rounding are not publicly published; confirm hook, bend and rounding from a licensed copy. |
| ACI / ASTM (US) | Standard 90°, 180° and 135° hook allowances by bar size and imperial / soft-metric bar masses. | Final cut-length rounding (ACI publishes no single rule) and your project's hook detailing. |
| Eurocode 2 (EU) | Minimum mandrel factors (4d up to 16 mm, 7d above 16 mm). | Bar diameters and masses come from national product tables; the bend deduction (2d per 90° bend) is a detailing assumption, not an EC2-published value. |
| AS 3600 / AS/NZS 4671 (Australia, NZ) | 180° and 135° hook and 90° cog dimensions by bar size, and mandrel factors. | Bend deduction and bar mass against your supplier's product tables. |
| CSA A23.3 / G30.18 (Canada) | M-bar nominal diameters and masses. | Hook, bend, mandrel and rounding allowances are detailing assumptions (not exposed by CSA) — confirm with your fabricator. |
| Generic (editable) | An approximate, fully editable fallback (12d hook allowance, 2d per 90° bend deduction). | Every value before fabrication — results from this preset are flagged approximate. |
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.
Each example reproduces the calculator's output exactly.
IS 2502 stirrup (shape VIII-A)
IS 2502- Given
- Two-legged stirrup, shape VIII-A
- Bar Ø8 mm
- Legs A = 250 mm, E = 150 mm
- Formula
L = 2(A + E) + 24d- Steps
- Straight legs: 2 × (250 + 150) = 800 mm
- Hook allowance: 24 × 8 = 192 mm
- 800 + 192 = 992 mm, rounded up to the nearest 25 mm
- Result
- Cutting length = 1000 mm
ACI bar with one 90° hook (#5)
ACI / ASTM- Given
- Straight bar with one 90° end hook
- Bar #5 (0.625 in)
- Straight length A = 60 in
- Formula
L = straight length + one 90° hook allowance- Steps
- Straight length: 60 in
- 90° hook allowance for #5: ≈ 9.8 in
- 60 + 9.8 ≈ 70 in
- Result
- Cutting length ≈ 70 in
ACI tie with two 135° hooks (#4)
ACI / ASTM- Given
- Tie with two 135° hooks
- Bar #4 (0.5 in)
- Straight length A = 48 in
- Formula
L = straight length + two 135° hook allowances- Steps
- Straight length: 48 in
- 135° tie-hook allowance for #4: ≈ 4.5 in each
- 48 + 2 × 4.5 ≈ 57 in
- Result
- Cutting length ≈ 57 in
Steel weight of a straight bar run
Generic / metric- Given
- Straight bars Ø12 mm
- Cutting length 6000 mm (6 m)
- 42 bars
- Formula
weight = unit weight × cutting length × number of bars- Steps
- Unit weight: 12² ÷ 162 = 0.889 kg/m
- Per bar: 0.889 × 6 = 5.33 kg
- Total: 5.33 × 42 ≈ 224 kg
- Result
- Total steel weight ≈ 224 kg
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.
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.
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.