| System | Value | Weight | Strands×Plies | Waste | Length Raw | Length Usable |
|---|---|---|---|---|---|---|
| Tex | 200 | 5 kg | 1×1 | 5% | 25,000 m | 23,750 m |
| Denier | 900 | 2 kg | 2×1 | 8% | 10,000 m | 9,200 m |
| dtex | 220 | 1.5 kg | 1×3 | 10% | 2,272.73 m | 2,045.45 m |
| Nm | 2.5 | 10 kg | 1×1 | 3% | 25,000 m | 24,250 m |
| Ne | 10 | 4 lb | 1×1 | 5% | 33,528 yd | 31,851.6 yd |
- Tex: L(m) = (W(g) / Tex) × 1000
- Denier: L(m) = (W(g) / Denier) × 9000
- dtex: L(m) = (W(g) / dtex) × 10000
- g/m: L(m) = W(g) / (g/m)
- Nm (meters per gram): L(m) = Nm × W(g)
- Ne (hanks per pound): L(yd) = Ne × 840 × W(lb)
- Select Length from weight to estimate how much line is on a roll.
- Select Weight from length to plan purchase quantities for a job.
- Choose the density system that matches your supplier sheet.
- Enter strands and plies only if your value is for one strand.
- Set a realistic waste percentage for knots, overlaps, and trimming.
- Press Submit to view results above this form.
- Use Download CSV/PDF to attach calculations to work packs.
Why yardage matters in site procurement
Construction teams often buy cord, mesh reinforcement yarns, and safety net edge lines by weight, then discover the delivered roll length is short. Yardage planning reduces stoppages, minimizes partial spool waste, and improves traceability in work packs. This calculator converts a supplier’s linear density specification into a practical length estimate, so you can match quantities to measured runs, tie points, and seam allowances.
Choosing the correct linear density system
Supplier sheets may specify Tex (grams per 1000 m), Denier (grams per 9000 m), dtex (grams per 10,000 m), or g/m. Use the same system to avoid conversion errors. Higher numbers in Tex or Denier indicate heavier material per unit length, which reduces achievable yardage for a given spool weight.
Strands, plies, and effective count
Many site applications use multiple strands in parallel or twisted plies for abrasion resistance. If your density value is for a single strand, the calculator multiplies density by strands×plies to get an effective assembly density. For count systems like Nm and Ne, the effective count is divided by strands×plies because combining strands reduces meters-per-gram performance.
Allowance and waste controls
Waste is rarely zero. Knots, overlaps, splice tails, edge trimming, and learning curves consume usable length. A 5–10% allowance is common for general tying and fastening, while higher values may be justified for repeated splices or aggressive trimming. The calculator reports both raw and usable length so procurement can order confidently.
Example data for quick verification
Example: Total weight 7.5 kg, Tex 250, strands 1, plies 2, waste 6%. Effective Tex = 250×2 = 500. Raw length = (7500 g / 500)×1000 = 15,000 m. Usable length = 15,000×0.94 = 14,100 m. Use this pattern to spot-check supplier rolls during receiving inspections.
1) Which system should I select if my datasheet lists Tex?
Select Tex and enter the value as shown. Tex is grams per 1000 meters, so matching the datasheet prevents unit confusion and gives the most reliable yardage estimate.
2) When do I set “density value refers to” as combined?
Choose combined when the supplier’s specification already describes the full assembly (for example, “2‑ply yarn, Tex 500”). In that case, strands and plies should not modify the effective density.
3) Why does adding strands reduce length for the same weight?
More strands increase total material per meter. If each strand has the same density, the assembly becomes heavier per unit length, so a fixed spool weight yields fewer meters or yards.
4) Can I use this for ropes or cords, not only yarn?
Yes. Any flexible line described by linear density (Tex, Denier, g/m, Nm, or Ne) can be estimated. For braided or coated products, results are approximate if density varies along length.
5) How should I choose the waste percentage?
Start with 5% for simple runs and ties. Use 8–15% when splicing, overlapping, or trimming is frequent. If your crew has measured historical loss, set waste to that observed percentage.
6) Why does “Weight from length” increase the required raw length?
The calculator assumes your target is usable length after losses. It divides the target by (1 − waste) to determine how much raw length must be purchased to finish the job without shortages.
7) What checks should I do before approving bulk purchases?
Verify the datasheet system, confirm whether the value is single strand or combined, and run one spot-check calculation against a weighed sample length. Keep a PDF export with the purchase order record.