This table is “current sizes” based on information provided at the manufacturer web sites and (added September 2007) for the corresponding US Knitting Needles, as shown at the yarnstandards.com resource website

You are welcome to link to this page or create your own.

Speaking of size, If Size Matters for your finished project, be sure to make a gauge swatch (I recommend TWO, one for reference and one to wash and dry as the project will be)

If you find any errors, be sure to let me know.

Wheat’s US-Metric Aluminum Crochet Hook Reference*

Wheat’s US-Metric Aluminum Crochet Hook Reference*
Alum Milli Meter	UK	US Yarn Std	Clover or Tulip	Clover Soft 5.3/4″	Clover Wood 6″	Pony Set Gift	Pony Pearl	Boye Alum 6″	Bates
2.00mm	_	A-0	2/o	-	-	-	-	-	-
2.25mm	1	-	3/o	-	-	-	-	B	B
2.30mm	_	B-1	3/o	-	B	-	-	-	-
2.50mm	_	-	4/o	C	-	2.50	-	-	-
2.75mm	2	-	-	-	C	-	-	C	C
3.00mm	_	C-2	5/o	D	-	3.00	-	-	-
3.25mm	3	-	-	-	-	-	-	D	D
3.50mm	4	D-3	6/o	E	-	3.50	-	E	E
3.75mm	5	E-4	-	-	D	-	F	F	F
4.00mm	6	F-5	7/o	F	E	4.00	G	-	G
4.25mm	_	G-6	-	-	F		-	G	-
4.50mm	7	-	7.5/o	G	G	4.50	-	-	-
5.00mm	8	_-7	8/o	H	H	5.00	H	H	H
5.50mm	9	H-8	9/o	I	I	5.50	I	I	I
6.00mm	10	I-9	10/o	J	J	6.00	J	J	J
6.50mm	10.5	J-10	-	-	-	6.50	-	K	K
7.00mm	_	K-10.5	-	-	-	7.00	K	-
7.50mm	_	-	-	-	-	7.50	-	-	-
8.00mm	11	-	-	-	-	8.00	-	-	L
9.00mm	13	L-8	-	-	-	-	M	N	-
10.00mm	15	N-13	-	-	-	-	-	-	N
12.75mm	17	-	-	-	-	-	-	-	N
15.00mm	19	-	-	-	-	-	-	-	N
19.00mm	35	-	-	-	-	-	-	-	N
25.00mm	50	-	-	-	-	-	-	-	N
Metric mm to in Conversions prepared using utilities found at: Metric Conversions.Org Hook Photos Used With permission and thanks to US Distributors: & Clover-USA and Muench Yarns-Pony Needles last updated 2007-May-02 © Wheat Carr

Once again,

* Based on Data Current as of February 2007.
* ALWAYS MAKE A GAUGE SWATCH
* ALWAYS check/measure the diameter of your hook
- Older Hooks often do NOT have the same Diameter as those made today.
-
* If you find an error, please do comment or email with the correction.
2007-05-03: Thanks to Kim Guzman for catching the typo for the Clover H-I-J