Crochet Hooks come in all different sizes, ranging from a tiny 0.6 mm all the way to a GIANT 16 mm! While there are numerous different measurements to consider when looking for your next hook, knowing which sizes work best for the project your planning can save you time and make your design look the best it could be!
1. Threading Hooks
Threading hooks are a particular kind of crochet hook that range from around 0.6mm-3mm. These hooks are designed for intricate details, such as crochet lace, and are the smallest type of hooks available. Crocheting with threading hooks is often considered a different section of crochet, referred to as "Thread Crochet", because it calls for crochet thread instead of standard yarn. Some of the crafts you could make using threading hooks are:
Doilies
Placemats
Coasters
Lace clothing/accessories
2. Amigurumi Hooks
Amigurumi almost always use standard crochet hooks, which range in size from about 2.25mm to 15mm. If you're in the USA, then these would range from a size "B" to a size "Q". For amigurumi, it's important to have small, condensed stitches so the stuffing does not show through! If you're using worsted weight yarn (category 4 yarn), a good range of hook size is around 3.5mm-4mm, or size "E" through size "G".
A helpful tip--if you see that your work is still looser than you want it to be, try moving a size down to adjust to your individual crochet style! (I sometimes use a 3.25mm hook to get the amigurumi extra-condensed!)
3. Crochet Clothing Hooks
If you're starting a crochet shirt, sweater, or brassiere, you will need to find a hook that allows for maximum coverage! Keeping the holes in between the stitches as small as possible will keep your apparel from being see-through, but of course if this is not of any concern than larger hooks are perfectly acceptable!
Using worsted weight yarn, a good range of hook size for crochet clothing is 2.75mm-3.5mm, or a crochet "C" hook to a crochet "E" hook.
4. Crochet Decor / Accessories Hooks
Crochet afghans, scarves, hats, and other large projects are perfect when using larger crochet hooks. Using bigger-sized hooks will actually speed up your progress and highlight that classic "crochet" look! These types of projects are also great for beginning crocheters, because the larger stitches are easier to see. Good hooks for crochet decor and accessories range from 4mm (G hook) to 15mm (Q).
While these suggestions can certainly make starting a project easier, always remember that if you don't like the way your project's size is turning out, switching to a smaller hook will tighten-up your stitches, and increasing your hook size will do the opposite! Happy crocheting :)