Knitting Needle Size Converter
Convert between US, metric (mm), and UK/Canadian needle sizes instantly. Enter any size to find all equivalents.
Find Equivalents
Type in any field to highlight the matching row below.
Full Conversion Table
| US Size | Metric (mm) | UK / Canadian | Recommended Yarn Weight |
|---|
About Needle Size Systems
Three major needle size systems are used around the world. The US system uses numbers (000 to 50) with higher numbers meaning larger needles. The metric system measures the needle diameter in millimeters and is the most universal. The UK/Canadian system (now largely obsolete) uses a reverse scale — higher numbers are smaller needles.
Always check your yarn label for the recommended needle size, then use this chart to find the equivalent in your preferred system. Gauge swatching is essential: even with the correct needle size, your tension may differ from the pattern's gauge.
Needle sizes are not perfectly standardized across manufacturers. A US 7 from one brand may measure slightly differently than another. The mm measurement is the most reliable specification.