Crochet Hook Size to Yarn Weight Converter
Convert between crochet hook sizes and yarn weights. Get perfect combinations for any project.
Hook size in millimeters
What crochet hook size should I use with different yarn weights?
Hook size depends on yarn weight: Lace/Fingering: 2-3.5mm, Sport/DK: 3.5-4.5mm, Worsted: 4.5-5.5mm, Aran: 5.5-6mm, Bulky: 6-9mm, Super Bulky: 9-15mm. These are guidelines - your tension matters. Always make a gauge swatch. If fabric is too tight, go up a hook size. If too loose, go down. Project type also affects choice - amigurumi needs tighter stitches than blankets.
Does hook material affect my crochet?
Yes. Metal hooks are smooth, fast, and good for silky yarns. Bamboo/wood grips more, preventing yarn slippage - better for beginners and plush yarns. Plastic is affordable but can bend. Tunian hooks are ergonomic for extended use. Choose based on yarn type and personal preference. Many crocheters prefer one material per yarn type. Try different hooks to find your preference.
How do I adjust for different yarn weights?
If your yarn weight matches recommended hook but fabric is wrong: For tighter stitches, use smaller hook. For looser, drapier fabric, use larger hook. Rule of thumb: 0.5mm change noticeably affects tension. Always check package for recommended hook size, then adjust to your gauge. Yarn label provides range, not exact numbers. Different patterns may need different hook sizes in same yarn.
Can I use any hook size with any yarn?
In theory yes, but results vary. A 4mm hook with super bulky creates a dense, stiff fabric. The same hook with lace creates holes. You can intentionally use wrong hook for effects: larger hook creates open, lacy fabric; smaller creates dense, sturdy fabric. This is a design choice, not a mistake. For functional projects, use recommended ranges. For art pieces, experiment freely.