Measure twice, make once
Knitting needle converter
Look up Craft Yarn Council metric and US knitting needle sizes.
Start with the calculator. Formula, assumptions, and limits are available when you need them.
Before you use this tool
Read the millimetre diameter stamped on the needle, or measure it with a needle gauge. Select that diameter to look up the listed regional size.
For example, 4 mm corresponds to US 6. A missing equivalent is not zero; keep the millimetre size when comparing needles.
Method and limits
Limits and rounding
Millimetres are authoritative. US labels vary by manufacturer, steel hooks use a separate reverse-numbered system, and blank US entries mean the CYC table gives no equivalent. Pattern gauge still decides the working size.