Construction & estimating · Site operations
Rebar cutting length and laps calculator
Cutting length for straight, L, U or closed-link bars with bend deductions and hooks, the laps needed for long runs from stock lengths, and total mass.
Standard: Bend deductions · hooks · lap splices (AS 3600 style)
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Inputs in the worked example
The live calculator starts with these values; change any of them and every result, check and diagram updates instantly.
| Input | Value | Unit |
|---|---|---|
| Shape | U-bar | |
| Bar diameter | 16 | mm |
| Dimension A | 2400 | mm |
| Dimension B | 450 | mm |
| End hooks | None | |
| Number of bars | 40 | |
| Continuous run length (laps) | 28 | m |
| Number of runs | 12 | |
| Stock length | 12 | m |
| Lap = k × db | 40 |
Worked example — results
| Result | Value | Unit |
|---|---|---|
| Cutting length | 3,236 | mm |
| Mass per metre (d²/162) | 1.580 | kg/m |
| Mass per bar | 5.11 | kg |
| Lap length | 640 | mm |
| Laps per run | 2 | |
| Run length incl. laps | 29,280 | mm |
| Total mass | 759.8 | kg |
- ✓ Cut length ≤ stock length — 3,236 mm
Method, formulas and assumptions
- Bend deduction: 2d (90°), 3d (135°), 4d (180°)
- Hooks: 90° 12d, 135° 10d, 180° 4d + 2d
- Laps = ⌈(run − stock)/(stock − lap)⌉
- Check the lap length against the development-length tool for the bar's actual stress and cover
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For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.