A 4mm crochet hook is a US G-6, and UK size 8. It’s a handy size to have for DK weight patterns, since it’s the size most DK yarn labels suggest by default.
What is a 4mm crochet hook used for?
This size is the standard match for DK weight yarn, and it also works for lightweight worsted when a pattern calls for a tighter fabric than the yarn’s usual gauge.
- Yarn weight: DK (light worsted).
- Common projects: lightweight garments, baby blankets, amigurumi.
How 4mm compares to nearby sizes
A 3.5mm hook tightens the fabric further in the same yarn, which helps when a pattern needs extra structure. Moving up to 4.5mm loosens the fabric slightly without the bigger jump a 5mm hook would make.
Frequently asked questions
What letter is a 4mm crochet hook?
A 4mm hook is a US G-6. In UK and Canadian sizing, the same hook is an 8.
Is a 4mm hook good for beginners?
Yes, along with 5mm it’s one of the two sizes I recommend most for a first hook, since DK and worsted are the two most common beginner yarn weights. It’s a size many crocheters reach for constantly.
What yarn weight uses a 4mm hook?
DK weight yarn is the standard match, with light worsted as a common second option.
See the full hook size chart
Compare 4mm against every other mm, US, and UK size in one table.