Free crochet tool
Yarn Substitution Calculator
A yarn substitution finder checks whether a different yarn can replace the one a pattern lists. Enter both yarns’ weight class, yards and grams per skein. It compares thickness using yards per 100 grams, rates the match as good, close or poor, and tells you how many skeins of the substitute to buy.
By the crochetpatterns.io editorial team · Reviewed · Editorial policy
Good match
Same weight class and similar thickness. Still swatch to confirm gauge.
What makes a good yarn substitute?
Match the weight class first, then the yards per 100 grams. Within 10 % usually crochets to the same gauge with the same hook. Within 20 % is workable but expect to change hook size.
Fibre matters too. Cotton has little stretch and more weight than acrylic, and wool blooms after washing, so drape and finished size can change even when thickness matches.
How is the number of skeins calculated?
Total yards equal the original skeins times the original yards per skein. Divide by the substitute yards per skein and round up — always buy by yards, never by skein count or grams alone.
Frequently asked questions
Can I hold two thin yarns together?
Two strands of a fingering yarn roughly equal one DK, and two DK roughly equal one bulky. Swatch to confirm.
Why compare yards per 100 g, not skein weight?
Skeins come in different weights. Yards per gram describes thickness regardless of skein size.
Do I still need to swatch?
Yes. Every yarn behaves differently; the finder narrows choices but a swatch confirms gauge.