How do I convert UK crochet terms to US terms?
UK and US crochet patterns use the same stitch names for different stitches, shifted by one step. A UK double crochet (dc) is a US single crochet (sc), a UK treble (tr) is a US double crochet (dc), and so on for each taller stitch. Swap every name one step and the stitches, counts and fabric stay the same.
Which crochet stitches change between UK and US terms?
Every stitch taller than a slip stitch changes name: the UK name is always one step taller than the US name for the same stitch. Chain is the same in both.
| Stitch | UK term | US term |
|---|---|---|
| Chain | chain (ch) | chain (ch) |
| Slip stitch | slip stitch (sl st, sometimes ss) | slip stitch (sl st) |
| Shortest basic stitch | double crochet (dc) | single crochet (sc) |
| Between the two | half treble (htr) | half double crochet (hdc) |
| Next tallest | treble (tr) | double crochet (dc) |
| Taller | double treble (dtr) | treble (tr) |
| Tallest common stitch | triple treble (trtr) | double treble (dtr) |
The names shift because the two systems count different things. UK names count the loops on the hook once you have pulled up the first loop, and US names count how many times you yarn over and pull through two loops. Both describe exactly the same stitches.
How can I tell whether a pattern uses UK or US terms?
Look for a stitch that exists in only one system. Single crochet (sc) appears only in US patterns, and half treble (htr) appears only in UK patterns.
- US terms: single crochet (sc) and half double crochet (hdc), plus gauge and hook sizes given as letters such as H-8.
- UK terms: half treble (htr), plus tension and British spellings such as colour.
- Not a clue on its own: double crochet (dc) and treble (tr) appear in both systems with different meanings, and skip and yarn over (yo) now turn up in UK patterns as well as US ones. Go by the stitch names.
If a pattern only ever uses dc and the photo shows short, dense stitches, it is almost certainly UK. A US pattern would call that stitch single crochet.
How do I convert a pattern row by row?
Change each stitch name one step down from UK to US (or one step up from US to UK), and leave every number alone. The stitch counts, chains and repeats do not change.
Here is the first round of a granny square, which makes 12 stitches and 4 corner spaces.
| UK terms | US terms |
|---|---|
| Make a magic ring. | Make a magic ring. |
| Round 1: ch 3 (counts as 1 tr), 2 tr into ring, ch 2. | Round 1: ch 3 (counts as 1 dc), 2 dc into ring, ch 2. |
| [3 tr into ring, ch 2] 3 times. | [3 dc into ring, ch 2] 3 times. |
| Join with sl st to top of beginning ch 3. (12 tr and 4 ch-2 spaces) | Join with sl st to top of beginning ch 3. (12 dc and 4 ch-2 spaces) |
The count checks out in both versions: 3 stitches in the first group plus 3 groups of 3 makes 12, and 1 chain space plus 3 more makes 4.
A plain row converts the same way. "Row 2: ch 1 (does not count as a st), 1 dc in each st to end, turn (20 dc)" in UK terms is "1 sc in each st to end, turn (20 sc)" in US terms.
What happens if I use the wrong terms?
Your stitch counts will still match, but the fabric will be the wrong height. Working a US double crochet where a UK pattern means double crochet gives a stitch roughly twice as tall.
The piece grows longer than planned, the fabric turns loose and lacy, and you use noticeably more yarn. If your work looks much taller than the photo after a few rows, check the terms before anything else.
Are yarn weights and hook sizes different too?
Yes. Hook sizes in millimetres are the same everywhere, but US patterns often give a letter as well, and the two countries name yarn weights differently.
| UK yarn weight | Nearest US yarn weight | Typical hook |
|---|---|---|
| 4-ply | fingering or sport | 3 to 3.5 mm |
| DK | DK or light worsted | 4 mm (G-6) |
| Aran | worsted or aran | 5 mm (H-8) to 5.5 mm (I-9) |
| Chunky | bulky | 6 mm (J-10) to 8 mm (L-11) |
| Super chunky | super bulky | 9 mm (M/N-13) or larger |
Always match your tension (UK) or gauge (US) with a swatch, whichever names the pattern uses. A yarn weight name is a guide, not a guarantee.
Do knitting patterns have the same problem?
No: knitting stitch names mean the same thing in the UK and US, so a knit or purl is the same stitch in both. Only some vocabulary differs.
The common pairs are stocking stitch and stockinette, cast off and bind off (UK patterns now use either), tension and gauge, and moss stitch, which UK patterns use for the stitch US patterns call seed stitch.
Can purlJam write my pattern in UK or US terms?
Yes: every crochet pattern purlJam writes uses the terms you choose, with the stitch names, abbreviations and spellings to match.
Set your crochet terminology on your profile and new patterns follow it, or say "UK terms" or "US terms" in your request to choose for that pattern.
Try it with a granny square blanket in UK terms, or browse the crochet patterns other makers have shared.