The crochet hook size chart covers all standard hook sizes with US letter/number labels, metric millimeter measurements, and UK/Canadian equivalents. Metric (mm) is the most universal sizing system — when in doubt, use mm to find the right hook.
Standard Crochet Hook Size Chart
| Metric (mm) | US Letter | UK / Canada | Yarn Weight | Best Uses |
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Steel Crochet Hooks (Thread Work)
| US Size | Metric (mm) | Thread Weight |
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How to Use a Crochet Hook Size Chart
Choosing the right hook from the crochet hook size chart ensures your finished project matches the pattern dimensions. Hook size, yarn weight, and your personal tension all interact to determine your gauge.
Always Make a Gauge Swatch
Before starting any pattern, crochet a 6-inch square swatch using the recommended hook and yarn. Count the stitches and rows per inch and compare to the pattern's gauge. If you have too many stitches per inch, go up a hook size; too few, go down. This step is critical for wearables and fitted projects.
Hook Material Matters
Aluminum hooks are the most common — smooth, affordable, and work well for most yarns. Ergonomic rubber-grip handles reduce hand fatigue for longer projects. Wood and bamboo hooks have more grab, which can help beginners maintain consistent tension. Tunisian crochet requires longer hooks with a stopper on one end.
Yarn Label Hook Recommendations
Most yarn labels include a recommended hook size. This is a starting point, not an absolute requirement. Many crocheters intentionally use a smaller hook (especially for amigurumi) to create a tighter fabric, or a larger hook for a looser, drapier fabric. Personal tension also varies significantly between crocheters.
Frequently Asked Questions
Is this crochet hook size chart free?
Yes, completely free with no signup required.
What is the most common crochet hook size?
The J/10 (6.0mm) hook is one of the most commonly used sizes, suitable for worsted weight yarn which is the most popular yarn weight for beginners. The H/8 (5.0mm) and I/9 (5.5mm) are also very popular all-purpose sizes.
How do I choose the right crochet hook size?
Match the hook to your yarn weight — yarn labels show a recommended hook size. Always make a gauge swatch before starting a project. If your swatch is too small, go up a hook size; too large, go down. The right size also depends on your personal tension.
What is the difference between US and UK crochet hook sizes?
US and UK sizing systems differ significantly. In the US, hooks are labeled with letters (B through S) and numbers. In the UK, hooks are labeled with numbers but the numbers mean different sizes than US. Both systems now include metric mm measurements, which is the most universal standard.
What is the smallest crochet hook size?
Steel crochet hooks used for thread work come in sizes 00 through 14, with size 14 being the smallest at 0.60mm. For standard yarn work, the B/1 (2.25mm) hook is the smallest common size.
What size hook for amigurumi?
Amigurumi (crocheted stuffed toys) typically uses a smaller hook than the yarn label recommends — usually going down 1-2 sizes to create a tighter fabric that prevents stuffing from showing through. A D/3 (3.25mm) or E/4 (3.5mm) hook with worsted weight yarn is common for amigurumi.