Wraps per inch calculator.
Wrap your yarn, count the wraps, and find its weight in a tap. Perfect for hand-spun skeins and unlabelled yarn.
Tip: wrap snugly around a ruler without squashing the yarn or leaving gaps, then count.
| Wraps per inch | Yarn weight | Typical use |
|---|---|---|
| 35+ | Cobweb | Fine lace, shawls |
| 22–34 | Lace | Lace shawls, doilies |
| 19–21 | Light fingering | Fine socks, shawls |
| 16–18 | Fingering / Sock | Socks, lightweight knits |
| 14–15 | Sport | Baby garments, light sweaters |
| 12–13 | DK | Sweaters, accessories |
| 10–11 | Worsted | Sweaters, hats, blankets |
| 8–9 | Aran | Warm sweaters, cushions |
| 7 | Bulky | Quick projects, outerwear |
| ≤6 | Super bulky | Chunky knits, rugs |
Charts vary by a wrap or two between sources, so treat WPI as a guide, not a precise rule. Yarn weight also depends on fibre and twist.
How to measure wraps per inch
- Find a ruler, or a WPI gauge, with a clear one-inch span.
- Wrap your yarn around it, laying each wrap snugly beside the last, with no overlapping, no gaps, and without stretching or squashing the yarn.
- Count the number of wraps that fill exactly one inch. That number is your WPI.
- Type it in above, or check it against the table, to find the yarn weight.
WPI is the spinner's quick way to judge a finished yarn against commercial weights, handy for matching a pattern or labelling your hand-spun. For more precise records, spinners also track grist (length per unit weight), which Spindrift calculates for you alongside plying ratios and shrinkage.
Keep every yarn on record.
Spindrift remembers the WPI, grist, fibre, and wheel settings for every skein you spin, so you can recreate a yarn you love. Free to download.
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