How to use this calculator
- Enter or choose machines.
- Enter or choose average needles per machine.
- Enter or choose needle changes per day.
- Enter or choose working days.
- Enter or choose breakage allowance.
- The needles needed updates as you type. Use Copy result or Share to keep it.
Method
Needles = ⌈Machines × Needles per machine × Changes per day × Days × (1 + Breakage%)⌉; Packs = ⌈Needles ÷ Pack size⌉
- Changes per day
- how often each needle is replaced under your policy
- Breakage%
- extra needles for breakage and damage
Worked example
- Planned = 50 × 2 × 1 × 26 = 2,600 needles.
- With 10% breakage: 2,600 × 1.1 = 2,860.
- Packs = 2,860 ÷ 10 = 286, costing 286 × 4 = 1,144.
Fifty machines changing two needles daily for 26 days need 2,860 needles, 286 packs.
What the result means
Use the result to set a monthly needle budget and a minimum stock. Compare it with actual issues from the needle register to spot unusual breakage.
Assumptions and limits
- All machines run every working day.
- Breakage is a flat percentage on top of planned changes.
- Different needle systems and sizes must be budgeted separately.
Questions
How often should needles be changed?
It depends on fabric, thread and your buyers’ requirements. Many factories change needles on a fixed schedule; enter yours as changes per day.
Why keep a needle register?
Many buyers require every broken needle to be accounted for, so needle issues are logged and matched to returned pieces.