Yarn Weights | Tips for Understanding

Matching yarn to a pattern can be complicated if you don’t understand how to read yarn weights on labels. What does it mean when your pattern calls for sport yarn or Aran weight yarn or 4-ply worsted?  Here is a guide.

Types of Yarn:

First, ignore information about plies unless it refers to a specific brand, such as “Brand XYZ 3-ply.”  Plies are the threads that are twisted together to make finished yarn.  Singles are the spun fibers after one pass through the spinner.  When singles are twisted together to make thicker yarn, the resulting yarn is 2-ply, 3-ply, etc.  This refers to the number of plies, not the weight of the finished yarn.  Thus a 4-ply in one variety of yarn could be thinner than a 3-ply of another variety.

Second, names can be helpful.  From lightest to heaviest, typical names are: lace, fingering or sock, sport, DK (double knitting), worsted, bulky, super bulky.  Because words like bulky or chunky or are not standardized, however, there is an even better way to describe yarn weights: the Standard Yarn Weight System of the Craft Yarn Council.

Yarn Weights:

This system is found on most yarn ball labels.  It is based on numbers from 0 to 7, with 0 being the finest yarn to be knit or crocheted with the maximum number of stitches per inch/centimeter. Here is a summary:

  • 0-Lace includes size 10 crochet thread and the lightest fingering yarn.  Knit gauge is around 9 stitches per inch.
  • 1-Super Fine includes most fingering, sock, and light baby yarn.  Knit gauge is 7-8 stitches per inch.
  • 2-Fine includes sport and some baby yarn. Knit gauge is around 6 stitches per inch.
  • 3-Light includes DK (double knitting) and light worsted yarns. Knit gauge is 5-6 stitches per inch.
  • 4-Medium is the most common weight and is often called worsted, afghan, or Aran.  Knit gauge is 4-5 stitches per inch.
  • 5-Bulky is often labelled chunky, craft, or rug yarn. Knit gauge is 3-4 stitches per inch.
  • 6-Super Bulky may be known as bulky, super bulky, or roving.  Knit gauge is  2-3 stitches per inch.
  • 7-Jumbo may be labelled jumbo or roving.  Anything less than 2 stitches per inch falls in this category.

Finally, you may have a pattern that refers to yarn weight in wraps per inch (wpi,) which is a measure used by hand spinners.  The more wraps per inch, the finer the yarn.  In this case, look at the gauge and compare to the Standard Yarn Weight System.


Understanding how yarn is labeled by weight is important when matching yarn to pattern gauge.  Especially, If your pattern calls for 6 stitches per inch, you know to look at the 2 or 3 yarn weights.  Then swatch until you have a yarn and needle combination that gives you the correct gauge for your pattern.  If you are using an old pattern, use the gauge rather than the description of the yarn used (which is probably no longer manufactured) in order to find a modern yarn that will work with your vintage pattern.  Yarn weight is also a tool for substituting different brands for the yarn recommended in a pattern. 





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