Turn a yarn weight and its count into the total length you'll get — in metres and kilometres — routed through Tex with the standard, exact conversion factors. The length math is exact for a clean cone; real production also loses a little to knitting waste and plied yarns, so add an allowance before you place a yarn order.
⚠️ The length is exact; the order size is not. The metres-per-gram math uses fixed, standard count factors, so the length of yarn on the cone is not an estimate. But a real order also loses yarn to knitting take-up, plies, sampling and rejects — typically 5–15% — so add your own waste allowance, and enter the folded count for plied yarns. Confirm the effective count and metreage at sampling before committing a purchase order.
Every yarn count fixes how many metres sit in a gram. Metric count (Nm) is metres per gram directly; Ne, Tex and denier say the same thing in different units.
Your count becomes Tex (grams per 1,000 m) first, then the length drops straight out: grams × 1,000 ÷ Tex. One formula covers all four systems.
These are defined ratios, not averages. 1 kg of Nm 30 is always ~30 km of yarn on the cone — no estimation in the number itself, only display rounding.
Knitting take-up, plies and reject margin all sit on top. Treat the result as the theoretical yarn, then add your own allowance before ordering.
Convert your count to Tex, then read the length straight off it. For metric count there's a clean shortcut — kilometres per kilogram simply equals the Nm number:
length (m) = weight (g) × 1000 ÷ Tex Tex = 1000 ÷ Nm Tex = 590.5 ÷ Ne Tex = denier ÷ 9 km per kg = Nm (metric shortcut) Nm 30, 1 kg → 30,000 m ≈ 30 km How far one kilogram of yarn stretches at common metric counts — a quick sanity check for the number above:
| Yarn count | Tex | Length per 1 kg |
|---|---|---|
| Nm 10 | 100 | 10,000 m · 10 km |
| Nm 20 | 50 | 20,000 m · 20 km |
| Nm 28 | 35.7 | 28,000 m · 28 km |
| Nm 30 | 33.3 | 30,000 m · 30 km |
| Nm 40 | 25 | 40,000 m · 40 km |
| 2/30 Nm (≈ Nm 15) | 66.7 | 15,000 m · 15 km |
Not sure which system your spec is in? Convert it first with the yarn count converter. To turn metreage into a real order, pair this with the yarn consumption estimator for grams per garment, then price it with the knitwear cost calculator and yarn cost per garment calculator. See every free tool on the tools hub, or start with our knitwear manufacturer overview.
Length in metres equals the yarn weight in grams times 1,000, divided by the Tex value (grams per 1,000 metres). This tool converts your count to Tex first — Tex = 1000 ÷ Nm = 590.5 ÷ Ne = denier ÷ 9 — then applies the formula. For example, 1 kg of a Nm 30 yarn (Tex 33.3) gives 1,000 × 1,000 ÷ 33.3 ≈ 30,000 metres, or about 30 kilometres.
Because a yarn count is a fixed weight-to-length ratio. Metric count (Nm) is literally metres per gram, so a Nm 30 yarn holds 30 metres in every gram — 30 kilometres per kilogram. Tex, Ne and denier express the same relationship in different units, which is why the calculator routes every input through Tex as a common basis before working out the length.
Yes — read it in reverse. If you know the total length you need, or the grams of yarn a garment consumes, this shows how far a given weight of yarn stretches so you can size a purchase order. Add a realistic waste allowance on top — knitting loss, take-up, sampling and reject margin, often 5–15% — because the formula returns the theoretical yarn on the cone, not the fully-knitted output.
No — it gives the exact theoretical length of the yarn as counted, with no deductions. For a folded or plied yarn, enter the resulting folded count (a 2/30 Nm folds to about Nm 15), not the single, so the length reflects the yarn as it is actually knitted. For a production order, add your own waste percentage; if a supplier's count is ambiguous, send it to us and we'll confirm the effective count and metreage.
Send your yarn spec and tech pack and we'll reply within one business day with pricing, a sample timeline and an honest read on count, metreage and waste allowance.