At Joeriaknits, we show both the metric and US sizing for all of our knitting needles and crochet hooks listed in our shop. Both US and metric sizing also appears on the packaging and on all the hooks and needles. If you inherited needles and hooks from your mother or grandmother, they might only show US or even European sizing. Canada went metric on April 1, 1975 and for some of us who grew up with the US imperial measurements we tend to rely on both measurements.
- Metric sizing is based on millimetre measurements and is commonly used in many parts of the world, including Canada, Europe, Australia, and New Zealand. It provides a precise measurement for needle sizes, making it easier to select the appropriate size for your project.
- US sizing is based on a numbering system ranging from 0 to 70, with smaller numbers indicating thinner needles and larger numbers indicating thicker needles. US sizing can be helpful for knitters who are accustomed to this system or prefer the familiarity of the numbering scheme.
- When converting between metric and US sizes, it's important to note that there is not always an exact conversion between metric and US sizes. While there are general conversions available, the correlation may not be consistent across all brands or manufacturers. This is because different manufacturers may have slight variations in their sizing standards. Therefore, it's a good idea to check a reliable conversion chart such as the one below.
Regardless of the number, letter or millimetre sizing, always complete a gauge swatch and compare it to the pattern gauge information. If your swatch is larger than the pattern gauge, redo a swatch using a smaller hook or needle. Conversely, if your gauge swatch it too small, redo it using a larger hook or needle to obtain the gauge indicated in the pattern.
Knitting Needle Sizes
| Millimetre Range | U.S. Size Range |
|---|---|
| 1.50 mm | 000 |
| 1.75 mm | 00 |
| 2 mm | 0 |
| 2.25 mm | 1 |
| 2.75 mm | 2 |
| 3 mm | |
| 3.125 mm | 3 |
| 3.25 mm | 3 |
| 3.50 mm | 4 |
| 3.75 mm | 5 |
| 4 mm | 6 |
| 4.25 mm | 6 |
| 4.50 mm | 7 |
| 5 mm | 8 |
| 5.25 mm | 9 |
| 5.50 mm | 9 |
| 5.75 mm | 10 |
| 6 mm | 10 |
| 6.50 mm | 10 ½ |
| 7 mm | |
| 8 mm | 11 |
| 9 mm | 13 |
| 10 mm | 15 |
| 12.50 mm | 17 |
| 12.75 mm | 17 |
| 15 mm | 19 |
| 19 mm | 35 |
| 25 mm | 50 |
| 35 mm | 70 |
Crochet Hook Sizes
| Millimetre Range | U.S. Size Range |
|---|---|
| 2.25 mm | B-1 |
| 2.50 mm | |
| 2.75 mm | C-2 |
| 3.125 mm | D |
| 3.25 mm | D-3 |
| 3.50 mm | E-4 |
| 3.75 mm | F-5 |
| 4 mm | G-6 |
| 4.25 mm | G |
| 4.50 mm | 7 |
| 5 mm | H-8 |
| 5.25 mm | I |
| 5.50 mm | I-9 |
| 5.75 mm | J |
| 6 mm | J-10 |
| 6.50 mm | K-10 ½ |
| 7 mm | |
| 8 mm | L-11 |
| 9 mm | M/N-13 |
| 10 mm | N/P-15 |
| 11.50 mm | P-16 |
| 12 mm | |
| 15 mm | P/Q |
| 15.75 mm | Q |
| 16 mm | Q |
| 19 mm | S |
| 25 mm | T/U/X |
| 30 mm | T/X |
Source: Craft Yarn Council's
www.YarnStandards.com
NOTE ABOUT STEEL HOOKS:
Steel crochet hooks are generally used with lace weight yarns and crochet threads. They are sized differently than regular hooks: the higher the number, the smaller the hook, which is the reverse of regular hook sizing. The smallest steel hook is a #14 or .9 mm; the largest is a 00 or 2.7 mm.
Steel Crochet Hook Sizes
| Millimetre Range | U.S. Size Range |
|---|---|
| 3.50 mm | 00 |
| 3.25 mm | 0 |
| 2.75 mm | 1 |
| 2.70 mm | 00 |
| 2.55 mm | 0 |
| 2.35 mm | 1 |
| 2.25 mm | 2 |
| 2.20 mm | 2 |
| 2.10 mm | 3 |
| 2 mm | 4 |
| 1.90 mm | 5 |
| 1.80 mm | 6 |
| 1.75 mm | 4/0 |
| 1.70 mm | 5 |
| 1.65 mm | 7 |
| 1.60 mm | 6 |
| 1.50 mm | 8/7/2 |
| 1.40 mm | 9/8 |
| 1.30 mm | 10 |
| 1.25 mm | 9/4 |
| 1.15 mm | 10 |
| 1.10 mm | 11 |
| 1.05 mm | 11 |
| 1 mm | 12/6 |
| 0.95 mm | 13 |
| 0.90 mm | 14/8 |
| 0.85 mm | 13 |
| 0.75 mm | 14/10 |
| 0.60 mm | 12 |