YarnScope
Issue № 001Spring / 2026Klaipėda · A stash tracker for serious crafters
05The Maths · How much yarn

How much yarn do I need? A weight calculator that respects gauge.

The honest formula is length × gauge × pattern factor. The dishonest formula is 'feels about a skein'. YarnScope does the honest math, and the table below covers the simple cases without opening the app.

The honest formula

Total yarn needed = finished length × gauge × pattern factor, plus headroom. In plain English: the further it knits, the slower it knits, and the bigger the surface area, the more yarn you need. Stockinette eats less than cables; cables eat less than stranded colourwork; everything eats less than oversize ease.

Quick estimates — adult garments

Yardage ranges below are for a standard adult Medium in stockinette. Adjust as noted.

  • Socks (pair) — fingering: 350–450 yds · sport: 300–400 yds
  • Hat (slouchy) — DK: 150–250 yds · worsted: 100–200 yds
  • Cowl — DK: 200–300 yds · worsted: 150–250 yds · bulky: 100–200 yds
  • Shawl (light, triangle) — fingering: 400–600 yds · lace: 500–800 yds
  • Cardigan (raglan, mid-hip) — DK: 1,100–1,500 yds · worsted: 900–1,300 yds
  • Pullover (drop-shoulder, hip) — DK: 900–1,200 yds · worsted: 800–1,100 yds
  • Oversize tunic — worsted: 1,300–1,800 yds · bulky: 1,000–1,400 yds
  • Blanket (50×60 inches) — worsted: 1,800–2,400 yds · bulky: 1,200–1,800 yds

Add 50–100% for stranded colourwork. Add 15–25% for dense cables and full-coverage lace. Always add 10% for swatching.

When the math fails

The formula relies on stockinette as the baseline. It breaks down on:

  • Variegated yarns — pooling and flashing can change the effective gauge mid-skein
  • Heavy texture — dense bobbles, cables, brioche can double the yardage of flat sections
  • Mixed colour blocks — every additional colour adds 5–10% for ends-weaving and joins
  • Drape-sensitive garments — a slinky linen or silk knit at "loose" gauge uses far less than the same weight in wool

For these cases, swatch generously. A 4-inch swatch is honest data; a 2-inch swatch is wishful thinking.

How YarnScope handles it

Pro stash owners use YarnScope’s Pattern → Yarn matching instead of the formula. You tell us the pattern’s weight, total yardage requirement, gauge, and colourwork status. We surface every skein in your stash that has the right weight, the right yardage (with headroom), and ideally a matching dye lot block. Reserved skeins stop showing in available filters. When the project finishes (or you frog it), the reservation releases.

Questions about the maths

How accurate are the quick estimates below?
Within about 15% for a stockinette adult garment in the listed weight category. Cables, lace, colourwork, and oversize ease push the requirement up; cropped silhouettes pull it down. Always add 10% headroom for swatching and frogging.
Why does YarnScope ask for gauge, not just weight category?
Two DK yarns can knit to wildly different gauges depending on hand, needle size, and fibre. The honest formula multiplies length by stitches-per-inch, not by an abstract weight name.
What about colourwork (Fair Isle, intarsia)?
Stranded colourwork uses 1.5× to 2× the yarn of a flat stockinette of the same area. The calculator inside YarnScope Pro offers a colourwork toggle that applies a 1.75× factor by default.
Will YarnScope tell me which stash skein matches the pattern?
Yes. Enter the pattern's weight, yardage requirement, and gauge. Pattern → Yarn matching surfaces every skein in your stash that could plausibly work, ranked by yardage headroom and dye-lot continuity.
What if my pattern lists yardage in metres and I bought yarn in yards?
YarnScope converts internally. 1 yard = 0.9144 metres; the calculator quietly handles both, and the UI shows your preferred unit.