Crochet hook-size converter
Compare common metric and US non-steel hook labels.
How it works
Labels vary by brand and country. Millimeter diameter is the clearest reference; this table covers common US non-steel hooks and traditional UK equivalents where available. Steel hooks use a different numbering system and are excluded.
A worked example
A 4 mm hook is commonly US G/6 and traditional UK 8. Always check the manufacturer’s millimeter marking and then make a gauge swatch.
Reference: Craft Yarn Council standards