Rebar Cutting Calculator & Cut List Optimizer

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Rebar Cutting Calculator & Cut List Optimizer

Last updated: Β·MethodologyΒ·FAQsΒ·Sources
1D rebar stock optimization & fabrication planning

Turn Approved Rebar Lengths into Practical Cutting Patterns

Enter the approved BBS cutting lengths, keep every diameter and grade separate, use existing inventory before purchases, account for cutting loss and stock trim, classify reusable remnants, and generate repeatable graphical cutting patterns with purchasing, weight, cost and verification.

This calculator answers a different question from the Rebar Calculator: it does not decide how much reinforcement a slab needs. It starts after the BBS/cutting lengths are known and answers, β€œHow should I cut my 6 m / 9 m / 12 m stock bars with minimum waste?”

New here? Start with a ready-made example

You do not need to understand every field before trying the optimizer. Choose one example below. The calculator will fill the required bars and matching stock automatically, run the optimization, and show the graphical cutting plan.

1. Load an exampleUse a valid sample job so every required diameter and grade has matching stock.
2. Read the resultStart with the blue KPI cards, then look at the coloured stock-bar cutting patterns.
3. Replace with your jobEdit the bar marks, cutting lengths, quantities and stock rows, then click Optimize again.
Demo loaded automatically: Beginner Ø16 example. Scroll to the result or edit the sample values and run it again.
1

Choose units & optimization rules

All stock and cutting lengths use the selected length unit. Rebar diameter remains in millimetres so different size groups cannot be mixed accidentally.

Material lost by saw/disc/shear allowance. Use 0 where appropriate.
Total length reserved and not available for pieces.
2

Enter required bars from the BBS

Each row is a finished reinforcement item. The optimizer groups by diameter + grade, so Ø16 Grade 500 will never be cut from Ø12 or from another grade.

Bar markA simple ID such as B1, B2 or S1 from the BBS.
Member / locationWhere the bar is used, for example β€œBeam bottom”.
Ø mm + GradeThe bar size and steel grade. Stock must match both.
Cut lengthThe approved finished cutting length of one piece.
QtyHow many identical finished pieces are required.
ImportantDo not enter slab length or beam length here unless that is the approved cutting length.
Bar markMember / locationØ mmGradeCut lengthQty
Bulk paste required bars from Excel / CSV

One row per line: Bar Mark, Member, Diameter mm, Grade, Cut Length, Quantity. Tabs or commas are accepted.

3

Enter inventory & purchasable stock

Quantity available is your current yard/workshop inventory. Keep β€œCan purchase?” on only for standard stock sizes the optimizer is allowed to order. Price is per full stock bar.

Stock lengthThe full straight bar available from the yard/supplier, e.g. 12,000 mm.
Qty availableFull bars already in inventory before buying anything.
Can purchase?Choose Yes if the optimizer may order more of this exact size/grade/length.
Price / barCost of one full stock bar. Use 0 if you only need the cutting plan.
Match ruleRequired Ø16 Grade 500 needs stock entered as Ø16 Grade 500.
Beginner tipIf unsure, load Example 1 above and change only one value at a time.
Ø mmGradeStock lengthQty availableCan purchase?Price / bar
Bulk paste stock from Excel / CSV

One row per line: Diameter mm, Grade, Stock Length, Available Qty, Price/Bar, Can Purchase (Yes/No).

Ready to calculate?
The required bars and stock must have the same diameter and grade. If the calculator cannot complete a job, the message below will tell you which group is missing or cannot fit.

Table of contents

What the result meansHow to use the optimizerWorked exampleCommon mistakesAssumptions & limitationsQuestions & answersSourcesMethodology
What the optimized result means

Stock bars used includes inventory bars and the purchased bars actually needed by the cutting plan. Bars to order is the purchase shortage after the selected buffer. Finished-piece utilization is finished rebar length divided by the full stock length used. True scrap includes entered trim, cutting loss and remnants below the reusable threshold. Reusable offcuts are deliberately kept separate because they remain usable inventory.

How to use the Rebar Cutting Optimizer
  1. Choose the length unit used by the BBS and stock list.
  2. Set realistic cutting loss, unusable trim and the minimum offcut worth keeping.
  3. Enter every required bar mark with its approved cutting length, diameter, grade and quantity.
  4. Enter current stock quantities and the standard stock sizes that may be purchased.
  5. Enter price per full stock bar if you want purchase-cost optimization and cost results.
  6. Run the optimizer and check the required-vs-produced table first.
  7. Issue the grouped workshop summary and graphical cutting patterns only after verifying dimensions and fabrication assumptions.
  8. Keep reusable offcuts and add them back to stock for the next job.
Worked example

Suppose Ø16 Grade 500 requires 12 Γ— 4,250 mm bars and 8 Γ— 2,850 mm bars, while Ø10 Grade 500 requires 30 Γ— 1,720 mm links. Available/purchasable stock is 12,000 mm. The optimizer treats the Ø16 and Ø10 requirements as separate material groups, uses any entered inventory first, then opens only matching purchasable stock. It tests several practical piece orders and stock-selection strategies and keeps the plan that best matches the selected objective.

Each used bar is reported as finished pieces + cutting loss + trim + leftover. Leftover at or above the reusable threshold is retained; smaller leftover is true scrap.

Common rebar cutting-plan mistakes
  • Mixing different bar diameters or grades in one stock pool.
  • Entering member dimensions instead of approved cutting lengths.
  • Ignoring cutting/shear loss, end damage or unusable mill ends.
  • Calling every leftover β€œwaste” even when it is large enough to reuse.
  • Applying purchase buffer to all stock instead of only the shortage to buy.
  • Using aggregate total length to order bars without checking individual cutting combinations.
  • Sending an optimized plan to fabrication without verifying the issued BBS revision.
Assumptions & limitations
  • This is a one-dimensional cutting-stock optimizer for straight stock bars and approved finished cutting lengths.
  • It does not calculate structural reinforcement demand, development length, lap length, hook geometry or code-specific bend deductions.
  • The optimization engine is a fast deterministic multi-strategy heuristic; it is designed to produce strong practical plans but does not claim a mathematically proven global optimum for every possible large cutting-stock problem.
  • Stock rows are interchangeable only when diameter and grade match exactly.
  • Price is per stock bar. Existing inventory is treated as already owned; purchase cost includes only the new order quantity.
  • Nominal weights use 7,850 kg/mΒ³ and may vary slightly from supplier/manufacturer values.
Fabrication note: Confirm the BBS revision, cutting tolerance, cutting method, bar identification and site/workshop requirements before issuing a cutting sheet.
Questions about rebar cut lists & stock optimization

Is this the same as a rebar quantity calculator?

No. A quantity calculator starts from slab dimensions and spacing. This optimizer starts from finished cutting lengths and decides how to cut those pieces from available stock bars.

Why are diameter and grade mandatory?

They define whether stock is physically interchangeable. The optimizer never uses one diameter/grade group to satisfy another.

What is true scrap?

In this calculator, true scrap is cutting loss + unusable trim + leftover shorter than the reusable threshold. Reusable offcuts are tracked separately.

Does it use inventory before new purchases?

Yes. Matching available inventory bars are opened before purchasable stock is added.

What does the purchase buffer do?

It increases only the shortage quantity that must be ordered. It does not change the cutting patterns or double-count the bars used in the optimized plan.

Is the result guaranteed to be the absolute mathematical optimum?

No. The engine tests several deterministic packing and stock-selection strategies and selects the best scored plan. This is fast and practical, but large cutting-stock problems can have many combinations.

Sources & further reading

The optimization methodology is implemented independently for CalcTypes; competitor pages are used as workflow references, not copied source code.

Methodology β€” how the optimizer works
  1. Convert stock and cutting lengths to millimetres for a common internal calculation.
  2. Group requirements and stock by exact diameter + grade.
  3. Expand required quantities into individual finished pieces.
  4. Reserve the entered unusable trim from every candidate stock bar.
  5. Use matching available inventory before opening purchased stock.
  6. Test several piece orders (long-first, short-first and mixed) and several stock-opening strategies (shortest adequate, longest adequate and lowest purchase cost).
  7. For each open stock bar, place the next piece in the tightest matching remaining space where it fits with cutting loss.
  8. Calculate physical cutting loss, trim loss and final leftover for every used bar.
  9. Classify leftover at or above the reusable threshold as reusable stock; smaller leftover is true scrap.
  10. Score the complete candidate plan according to the selected objective and keep the strongest candidate.
  11. Apply the purchase buffer only to the optimized purchase shortage, then calculate new-order weight and cost.
  12. Verify required and produced quantities by bar mark, diameter, grade and length.

True scrap = cutting loss + trim loss + short leftover

Finished-piece utilization = finished piece length / full stock length used Γ— 100%

Related rebar & cutting calculators

Rebar CalculatorStart from slab dimensions and spacing to estimate quantity, weight and cost.Estimate rebar β†’Bar Bending Schedule CalculatorBuild bar marks and approved cutting-length schedules before optimization.Build BBS β†’Cut List OptimizerGeneric 1D optimizer for non-rebar bars, rods, pipe, tube and timber.Open generic optimizer β†’

Important disclaimer

This is a material-planning and workshop-optimization aid. It does not replace structural detailing or an approved BBS. Verify all cutting lengths, grades, diameters, tolerances, cutting loss and stock availability before fabrication or purchasing.