Yarn Weight Comparison Chart

This chart compares yarn weights side by side using wraps per inch (WPI) and typical yardage per 100 g, so you can identify a yarn or substitute one weight for another.

Weight WPI Yards per 100 g
Lace 35 and up 400 to 800
Fingering 14 to 16 350 to 450
Sport 12 to 14 280 to 330
DK 11 to 13 230 to 260
Worsted 9 to 11 190 to 220
Aran 8 to 9 150 to 180
Bulky 7 to 8 100 to 140
Super Bulky 5 to 6 40 to 90
WPI identifies mystery yarn. Wrap the yarn snugly around a ruler and count wraps in one inch. The WPI tells you the weight class of an unlabeled skein.

See the Yarn Weight Chart and the Yarn Weight Converter.

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The calculators and tools on Formula Factory are provided for general guidance and informational purposes only. Results are estimates based on standard formulas and the values you enter — they do not constitute professional engineering, electrical, or architectural advice. Always verify calculations with a qualified professional before making decisions for any safety-critical, code-compliance, or commercial application. Formula Factory makes no representations or warranties as to the accuracy or completeness of any result, and accepts no liability for errors, omissions, or any outcomes arising from reliance on this information.