Crochet Hook Size Chart: US, UK and Metric
Use this crochet hook size chart to convert common hook sizes between US, older UK, and metric measurements, then check your gauge before starting.
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Gauge calculator
Your swatch becomes stitches and rows per inch, the number every other calculation on this site depends on.
Count across the middle of a blocked swatch.
Optional. Needed for any length math.
Most patterns quote gauge over 4 in.
Live gauge preview
5 stitches per inch, 7 rows per inch
Your gauge
Based on your blocked gauge. Unblocked swatches lie.
What this calculation does not account for
- Lace and openwork, which can open up dramatically after blocking.
- Colourwork, where tension differs from your plain-fabric gauge.
- Gauge drift between flat and in-the-round work. Measure in the way you'll actually make the piece.
Last updated 2 August 2026Found a wrong number? Tell us.
How to use this
- Knit or crochet a swatch at least 6 inches square, in the stitch pattern you'll actually use.
- Block it the way you'll block the finished piece, and let it dry completely. An unblocked swatch will give you a number that stops being true the first time you wash the garment.
- Measure across the middle, away from the edges, and count the stitches over 4 inches or 10 cm. Enter what you counted above.
Next step
Once you know your gauge, the pattern resize calculator converts a pattern's stitch counts to it.
Learn the method
Guides for this calculator