# Whats is the mm equivalent of US / old UK knitting needles?

When converting from US or old UK knitting needle sizes to mm, what are the conversions for these?

• @AllisonC Sorry, my previous comment was wrong. That question and this one have very similar answers, because the conversions somewhat overlap. It might be confusing for knitters not familiar with crochet, because US crochet hook sizes tend to use the letter system, not the number system. I think Catija's question and answer could be expanded to include both knitting and crocheting, but it would need editing. Commented Jan 23, 2020 at 14:59
• Sorry about that! I'd misread the two questions as being the same, then retracted it without realizing that it left a comment. Commented Jan 23, 2020 at 16:29
• @AllisonC I'll add a link to it in my answer, since they're pretty closely related. Commented Jan 23, 2020 at 16:50

Here's an overview of all the knitting needle sizes I know.

```Metric    UK        US
0.5mm     24        -
0.75mm    22        -
1.0mm     20        5/0
1.25mm    18        4/0
1.5mm     17        000
1.625mm   16        -
1.75mm    15        00
2.0mm     14        0
2.25mm    13        1
2.5mm     -         1.5
2.75mm    12        2
3.0mm     11        2.5
3.25mm    10        3
3.5mm     -         4
3.75mm    9         5
4.0mm     8         6
4.5mm     7         7
5.0mm     6         8
5.5mm     5         9
6.0mm     4         10
6.5mm     3         10.5
7.0mm     2         -
7.5mm     1         -
8.0mm     0         11
9.0mm     00        13
10.0mm    000       15
12.0mm    -         17
15.0mm    -         19
20.0mm    -         35
50.0mm    -         50
```

For crochet hooks, see: What is the conversion for UK and US crochet hooks to mm?

Here is a chart for metric/US/UK conversions with crochet hook sizes as welll:

``````Metric(mm)       US       UK      Crochet
2.0              1        14       --
2.25             1        13       B
2.5              1.5      --       --
2.75             2        12       C
3.0              2.5      11       --
3.25             3        10       D
3.5              4        --       E
3.75             5        9        F
4.0              6        8        G
4.5              7        7        --
5.0              8        6        H
5.5              9        5        I
6.0              10       4        J
6.5              10.5     3        K
7.0              --       2        --
7.5              --       1        --
8.0              11       0        L
9.0              13       00       --
10.0             15       000      --
12.0 - 12.75     17       --       --
15.0 - 16.0      19       --       --
19.0             35       --       --
20.0             36       --       --
25.0             50       --       --
``````

I've also attached a link below to a printable version that may be useful.

Knitting Needle Sizes and Conversion Chart