How is Yarn measured?

Although we say that yarn is organized by "weights", we do not organize it by the actual weight on the scale (in grams or kilos). Instead, the term "yarn weight" actually refers to the thickness of the thread of the yarn.

What determines the weight of the yarn?

The weight of a yarn is determined by measuring the diameter - or thickness - of a strand of yarn. The most common way to measure the diameter of a wire is with a method called wraps per unit, or WPU.

The Craft Yarn Council (CYC) has standardized a yarn weight system to help crafters select the appropriate yarn for their projects. This system categorizes yarn into seven weight classes, from delicate lace to thick jumbo yarn.