Yarn

Comparison Table

Knitting Needle & Crochet Hook Sizes

The Craft Yarn Council publishes standardized charts converting US knitting needle and crochet hook sizes to metric millimeter diameters. Needles run from US 000 (1.5 mm) to US 50 (25 mm); crochet hooks run from US B-1 (2.25 mm) to US T/U/X (25 mm). Because letter and number labels vary slightly by manufacturer, the millimeter size printed on the package is the reliable reference.

Comparison Table

Yarn Weight System

The Craft Yarn Council classifies yarn thickness on a 0 to 7 scale: 0 Lace, 1 Super Fine, 2 Fine, 3 Light, 4 Medium (worsted), 5 Bulky, 6 Super Bulky, and 7 Jumbo. The system standardizes the hook and needle size and gauge recommendations printed on yarn labels across manufacturers.