WPI

Wraps per inch

A way of measuring the thickness of your yarn. To measure WPI, wrap the yarn around a ruler until the wraps cover one inch of the ruler. Count how many wraps fit into one inch.

Yarn weight as measured by WPI

Yarn Weight WPI
Lace 30-40+
Super Fine 14-30
Fine 12-18
Light 11-15
Medium 9-12
Bulky 6-9
Super-Bulky 5-6
Jumbo 1-4

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