One of the most confusing things for crocheters, especially beginners, is discovering that the same stitch name can refer to two completely different stitches depending on whether a pattern uses US or UK terminology. This guide explains exactly how the two systems differ and how to convert between them so you can follow any pattern accurately.
Why Two Different Systems Exist
Crochet terminology developed somewhat differently in the United States compared to the United Kingdom and other regions that follow British conventions, such as Australia and much of Europe. Both systems describe the same physical stitches, but they assign different names to them, which means a pattern written in one system will produce a different result if worked using the other system’s stitch definitions. The Craft Yarn Council maintains a standardized reference for crochet terminology that many designers on both sides of the Atlantic use as a baseline.
The Core Difference
The most important thing to understand is that US and UK terms are offset by one “level.” What’s called a single crochet in the US system is called a double crochet in the UK system, and this offset continues through the taller stitches as well.
US to UK Conversion Chart
| US Term | UK Term |
|---|---|
| Single crochet (sc) | Double crochet (dc) |
| Half double crochet (hdc) | Half treble crochet (htr) |
| Double crochet (dc) | Treble crochet (tr) |
| Treble crochet (tr) | Double treble crochet (dtr) |
| Double treble crochet (dtr) | Triple treble crochet (trtr) |
| Slip stitch (sl st) | Slip stitch (sl st) |
| Yarn over (yo) | Yarn over hook (yoh) |
| Gauge | Tension |
Note that slip stitch remains the same in both systems, and the main difference for most beginner projects comes down to how single/double crochet and double/treble crochet are labeled.
Why This Matters So Much
If you work a pattern written in UK terms as though it were US terms—or vice versa—you’ll produce a fabric with a completely different stitch height and density than intended, since you’re substituting a different actual stitch for each instruction. This is one of the most common causes of a project turning out drastically different from the photo shown in a pattern, and it can also produce the kind of unevenness described in our guide on why crochet can look uneven.
How to Identify Which System a Pattern Uses
Patterns don’t always explicitly state which terminology system they follow, but there are a few reliable clues:
- Check the designer’s location or stated audience. Patterns from US-based designers or publications typically default to US terms, while UK, Australian, or European designers often use UK terms.
- Look for a terminology note. Many patterns, especially from larger publishers, explicitly state “US terms” or “UK terms” near the beginning.
- Check the abbreviations key. If “dc” is defined as a taller stitch involving a yarn over before inserting the hook, it’s likely UK terminology, since US double crochet also involves a yarn over but produces a shorter stitch than the equivalent UK treble.
How to Convert a Pattern Between Systems
If you prefer working in one system but have a pattern written in the other, you can convert it stitch by stitch using the chart above. Each instance of a stitch abbreviation in the original pattern gets replaced with its equivalent from the other system.
Example: A UK pattern instruction reading “dc in each st across” would become “sc in each st across” when converted to US terms, since UK double crochet corresponds to US single crochet.
Common Mistakes to Avoid
- Assuming all patterns default to your home terminology system without checking.
- Converting only some stitch types in a pattern and missing others, resulting in a mismatched fabric.
- Confusing “treble crochet” (UK) with “triple crochet,” which is a different, less standardized term sometimes used informally.
- Not checking terminology before starting a project where finished size or gauge matters significantly.
Tips for Better Results
- When starting a new pattern from an unfamiliar source, check the terminology system before beginning, not partway through.
- Keep a simple conversion chart on hand, especially when working patterns from international designers.
- If a pattern includes a photo, compare the expected stitch density in the image to your work-in-progress as an additional check that you’re using the correct terminology.
- When in doubt, patterns that state expected gauge can help confirm terminology, since a mismatched system will produce noticeably different stitch height and gauge results.
Frequently Asked Questions
Is one system more common than the other? This depends on the source. US terms are common in patterns published by US-based designers and platforms, while UK terms are common among British, Australian, and many European designers.
Do stitch symbols in charted patterns also differ between US and UK? Crochet stitch diagrams are generally based on the actual stitch structure rather than the terminology name, so a charted pattern is often easier to follow regardless of which written terminology system you’re used to.
Can I mix US and UK terms within the same project? No, mixing terminology systems within a single project will produce stitches of inconsistent height and density, since the same abbreviation represents different actual stitches in each system.
Does gauge differ between US and UK terms for the “same” pattern? Gauge is tied to the actual stitch being worked, not the name used for it, so as long as you correctly identify which system a pattern uses and work the corresponding stitches, gauge should match regardless of terminology.
How can I tell if I’ve been taught US or UK terms? Compare your understanding of basic stitch names against the conversion chart above. If what you call “double crochet” matches the taller UK stitch rather than the shorter US stitch, you likely learned the UK system.