Download the three charts shown above—with extra columns!—as a free PDF. See below. There was no room for this material in my newsletter issue about crochet hooks. It pairs well with this one: Deluxe Crochet Hook Diagram.
Hey there, New Crocheter?: On the face of it, crochet hook sizes are beginner-level stuff. Question one quirky thing and you can end up in a maze. I did. Over the years I’ve had five key realizations. They build on each other in a logical order, below. I wish I could have read this post when I started questioning! Bookmark this if you’re not quite ready for it yet. Better yet, add a comment about where you’re at.
Crochet Hook Sizes Explained
I originally created these charts for my own use.The PDF has more information than the three charts pictured at the top of this blog. For example, two more columns, and how to use the charts and understand the size increments. Each chart is a full-page size:
- All Steel Crochet Hook Sizes in 0.10 mm increments: 0.40 mm – 3.50 mm
- NON-Steel Crochet Hooks, medium-range in 0.25 mm increments: 1.75 mm – 7.75 mm
- NON-Steel Crochet Hooks, jumbo sizes in 1.00 mm increments: 8.00 mm – 36.00 mm
Crochet Hook Sizes, the Five Keys
1. I watch exactly where on the hook I make each stitch.
I especially watch the starting loop on the hook because it will become the top two loops of the new stitch. My goal is to avoid forming stitches on the tapered part (“throat”) of the crochet hook.
Some hooks have such a long throat that I can’t avoid making my stitches there. This is a big deal with some stitches. The taper will give my tall stitches loose top loops.
Pictured at right is my first crochet hook (green) and one of my current favorites (gold). My green crochet hook made my stitches look more stringy and uneven than they had to, even for a newer crocheter.
A big revelation for me (thank you Nancy Nehring) was that the crochet hook’s true size is where my stitches are made on it. So the other reason I watch where I make stitches on the hook is to know where to measure the hook size.
2. I treasure my slide gauge tool.
Needle gauges, the kind with holes, are everywhere. They’re even given out for free at yarn shops and conferences. I tossed them all out and only use a slide gauge. If I could find a reliable source for my favorite slide gauge I’d have it in my shop already. Lacis has had this one for a long time. It’s now also at JoAnn Fabrics, Amazon, Walmart, etc. Here’s another one. You can also search for millimeter calipers.
Once I know where on the hook I make my stitches (see #1 above), I measure that with a slide gauge or caliper. I get my true size of each hook in a jiffy. No forcing a hook in or out of the holes of a needle sizer with the risk of scratching the hook in the process!
When I did this with all of my crochet hooks, I found out that about a third of them were not the sizes I thought they were (based on how I use them).
3. I base my stitch gauge on my hook size.
At some point in my crochet life I realized why we have so many crochet hook sizes. When the stitch gauge is based on the hook size and not on the yarn thickness, or personal habit, some amazing crochet fabrics are possible! Starwirbel, Weightless, stretchy slip stitches, and many more.
There are two more reasons: it’s the way to get the most polished stitching gauge for each project. It also standardizes our results as an international crochet community.
Before this realization I thought the different hook sizes were there to make crocheting with different yarns more pleasant. “I think this yarn is too thick for this hook. Must mean I need a bigger hook size”. That’s a fine reason, but if it were the real reason for the sizes, we’d only need about eight sizes—one per yarn thickness category. See the How Many Crochet Hooks? section of my other crochet hook post.
4. I think in millimeter (mm) sizes.
Instead of the “H hook” of my childhood I now think “5 mm hook”. It has improved every day of my crocheting life. I no longer have to deal with traditional hook size systems that are riddled with overlaps and exceptions.
Not only that, the mm sizing makes it plain where there are gaps in the standard hook sizes, and how large each gap is. This in turn opened up to me a wonderland of in-between or nonstandard crochet hook sizes. Hello handmade crochet hooks, imported hooks, and other collectibles, including odd manufacturing runs of established brands.
5. The actual number of crochet hook sizes? Infinite.
The American Craft Yarn Council (CYC) maintains a chart of 29 steel and 28 non-steel crochet hook sizes according to American and British standards. It’s a good start and includes equivalent mm sizes. I build on it in my crochet hook sizing charts by adding Japanese hook sizes and placeholders for missing sizes.
The millimeter measure accounts for all possible hook sizes, including the sizing standards of other countries. I love seeing how US, UK, and Japanese hook sizes all fit together.
Does an infinite number of crochet hook sizes seem overwhelming? Every crocheter needs a different number of sizes. Check for yourself with my list of five factors.
How Did We Get Here?
I think of the non-metric crochet hook sizing systems as being two great crochet traditions (cotton/silk threads vs. wool yarns) that got mushed together, then sprinkled with sizing standards of different countries. It’s quite the heady brew.
Steel crochet hooks were designed for lace crochet with thread. Steel is very strong for even the finest hook sizes. They’re numbered from 00 to 14 (sometimes 16). The larger the number, the smaller the hook.
Non-steel crochet hooks, whether made of aluminum, wood, bamboo, plastic, or glass, get numbered and lettered sizes (from B to U so far) according to an American system. Sizing systems in other countries use different numbering systems. Unlike the steel sizes, the large the number, the larger the hook.
Let’s talk about the size “G” hook. The CYC lists three non-steel G hooks: 4.0 mm, 4.25 mm, and 4.5 mm. Each one is a useful size. Labeling all of them size “G” is unnecessarily confusing.
The Way of Peace
Just focus on the millimeter size. A crochet hook that measures 4.0 mm (on the part of the hook where you make the stitches) will always be that size for you. It won’t matter what it’s made of, where you live, or which country manufactured the hook. Feels peaceful, doesn’t it?