Knitting Needle Size Chart and Gauge Calculator
A knitting needle size chart matches US needle numbers to metric millimeters and the old UK and Canadian sizes. For example, US 8 is 5.0 mm. Use the chart to convert a size, then the gauge calculator to work out how many stitches and rows a project needs from your swatch.
Knitting needle sizes: US, mm and old UK
Brand labels vary, so match the millimeters first. A dash means there is no standard pairing.
| US | Metric | Old UK / Canadian |
|---|---|---|
| 000 | 1.5 mm | - |
| 00 | 1.75 mm | - |
| 0 | 2 mm | 14 |
| 1 | 2.25 mm | 13 |
| 1.5 | 2.5 mm | - |
| 2 | 2.75 mm | 12 |
| 2.5 | 3 mm | 11 |
| 3 | 3.25 mm | 10 |
| 4 | 3.5 mm | - |
| 5 | 3.75 mm | 9 |
| 6 | 4 mm | 8 |
| 7 | 4.5 mm | 7 |
| 8 | 5 mm | 6 |
| 9 | 5.5 mm | 5 |
| 10 | 6 mm | 4 |
| 10.5 | 6.5 mm | 3 |
| - | 7 mm | 2 |
| - | 7.5 mm | 1 |
| 11 | 8 mm | 0 |
| 13 | 9 mm | 00 |
| 15 | 10 mm | 000 |
| 17 | 12.75 mm | - |
| 19 | 15 mm | - |
| 35 | 19 mm | - |
| 50 | 25 mm | - |
| 70 | 35 mm | - |
Last reviewed October 23, 2026. Pairings are the widely published ones, rewritten in our own table.
Gauge calculator
Turn a swatch into a stitch count, or a stitch count into a finished size. Gauge is how many stitches and rows fit in one inch.
How to work out stitches and rows from your gauge
- Knit a swatch at least 4 inches square in your pattern stitch.
- Wash and dry it the way you will care for the finished project.
- Count the stitches and rows across 4 inches.
- Divide each count by 4 to get stitches and rows per inch.
- Multiply by the finished width and length you want.
Old UK and Canadian sizes
Old UK and Canadian needle sizes run backward compared with US numbers. A higher number means a thinner needle, from 14 for 2 mm down to 000 for 10 mm. You will meet them on vintage patterns and older needles. Where the old scale has no match, the chart shows a dash. If you also crochet, the crochet hook size chart uses a similar layout, and the yarn weight chart shows the usual needle range for each yarn weight.
Frequently asked questions
What size is a US 8 knitting needle in mm?
A US 8 knitting needle is 5.0 mm. Its old UK and Canadian equivalent is 6. US needle numbers go up as needles get thicker, while old UK numbers go down, which is why a chart helps. Brands can differ slightly, so check the millimeter size marked on your needles when a pattern gives only a number.
How do I convert knitting needle sizes?
Find the size you have in the US, metric or old UK column of the chart, and read across to the other two. The metric millimeter size is the measurement all makers agree on, so convert to millimeters first. A few millimeter sizes have no US number, and some US sizes have no old UK equivalent; those cells show a dash.
How do you calculate knitting gauge?
Knit a swatch at least 4 inches square in your pattern stitch, wash and dry it as you will the finished piece, then count stitches and rows across 4 inches. Divide each count by 4 for stitches and rows per inch. Enter them in the calculator above to get the stitches and rows for any size.
How many stitches do I cast on?
Multiply your stitches per inch by the width you want. With a gauge of 5 stitches per inch, an 18 inch piece needs 90 stitches. Round to the nearest number that fits your stitch pattern repeat, and add edge stitches if the pattern asks for them. The calculator also turns a stitch count back into a finished width.
What are old UK and Canadian knitting needle sizes?
Old UK and Canadian needle sizes run backward from US numbering: a higher number means a thinner needle, from 14 for 2 mm down to 000 for 10 mm. They appear on vintage patterns and older needles. The chart shows each old size beside its metric and US size, with dashes where no match exists.