🪡 Needle Size Converter
Convert knitting needle sizes US, metric and UK
About this calculator
The Needle Size Converter translates between US, metric (mm), and UK/Canadian needle sizing systems. Enter a size in any system to see the exact equivalents — for example US 8 equals 5.0 mm. Patterns from different countries use different conventions, and grabbing the wrong size 8 ruins gauge.
Tip: when a pattern's size falls between two metric options, choose based on your swatch, not the chart — manufacturers round differently, so measure your actual needles with a gauge tool.