Craft conversion charts

Patterns, needles, hooks and yarn are labelled in different systems in the UK, the US and the rest of Europe. This page puts the conversions UK makers look up most often in one place: knitting needle sizes, crochet hook sizes, yarn weights, UK vs US crochet terms and aida counts. Metric (mm) sizes are the most reliable reference: when in doubt, match the millimetre size printed on your needle, hook or ball band.

Knitting needle sizes: metric, old UK and US

Modern UK needles are sold in millimetres; older patterns use the old UK numbers, where a bigger number means a thinner needle. US sizes run the other way. Some conversions differ slightly between charts.

Metric (mm) Old UK size US size
2 mm 14 0
2.25 mm 13 1
2.75 mm 12 2
3 mm 11 2½ or 3 (charts vary)
3.25 mm 10 3
3.5 mm – 4
3.75 mm 9 5
4 mm 8 6
4.5 mm 7 7
5 mm 6 8
5.5 mm 5 9
6 mm 4 10
6.5 mm 3 10½
7 mm 2 –
7.5 mm 1 –
8 mm 0 11
9 mm 00 13
10 mm 000 15
12.75 mm – 17
15 mm – 19
19 mm – 35
25 mm – 50

More detail, including circular and double-pointed needles: knitting needle sizes explained.

Crochet hook sizes: metric and US

UK hooks are labelled in millimetres. US hooks use a letter and number; the letters do not always match exactly between brands, so check the millimetre size.

UK / metric (mm) US size Often used with
2.25 mm B-1 4ply
2.5 mm – 4ply
2.75 mm C-2 4ply
3.25 mm D-3 4ply
3.5 mm E-4 4ply, sport
3.75 mm F-5 Sport
4 mm G-6 Sport
4.5 mm 7 Sport, DK
5 mm H-8 DK
5.5 mm I-9 DK, aran
6 mm J-10 Aran
6.5 mm K-10½ Aran, chunky
7 mm – Chunky
8 mm L-11 Chunky
9 mm M/N-13 Chunky, super chunky
10 mm N/P-15 Super chunky
15 mm P/Q Super chunky

Yarn weights: UK names, US names and Craft Yarn Council numbers

The ball band is the final word: it gives the recommended needle size and tension. The ranges below are typical, not fixed rules.

UK name Common US name CYC number Needles (mm) Hook (mm) Typical uses
1ply, 2ply (lace) Lace, cobweb 0 Lace 1.5–2.25 Steel 1.4–1.6, or 2.25 Shawls, lace, christening wear
4ply Fingering, sock, baby 1 Super Fine 2.25–3.25 2.25–3.5 Socks, baby clothes, fine jumpers, colourwork
(no common UK name) Sport 2 Fine 3.25–3.75 3.5–4.5 Light garments, baby items
Double knitting (DK) Light worsted, DK 3 Light 3.75–4.5 4.5–5.5 Jumpers, cardigans, toys, blankets
Aran Worsted, aran 4 Medium 4.5–5.5 5.5–6.5 Cabled jumpers, hats, blankets
Chunky Bulky 5 Bulky 5.5–8 6.5–9 Quick jumpers, hats, scarves, rugs
Super chunky Super bulky 6 Super Bulky 8–12.75 9–15 Throws, cowls, statement hats
Jumbo / roving Jumbo 7 Jumbo 12.75 and larger 15 and larger Chunky throws, arm knitting

What each weight is best for: yarn weights explained.

UK vs US crochet terms

UK and US patterns use the same stitch names for different stitches. A UK double crochet is a US single crochet, so a pattern written in one system worked in the other comes out much taller or shorter than intended.

UK term (abbreviation) US term (abbreviation)
Chain (ch) Chain (ch)
Slip stitch (ss or sl st) Slip stitch (sl st)
Double crochet (dc) Single crochet (sc)
Half treble (htr) Half double crochet (hdc)
Treble (tr) Double crochet (dc)
Double treble (dtr) Treble (tr)
Triple treble (trtr or ttr) Double treble (dtr)

How to tell which terms a pattern uses: UK vs US crochet terms.

Cross stitch: aida counts, strands and needles

The count is the number of stitches per inch. The higher the count, the smaller the finished design. Strand and needle choices are common starting points; follow your chart or kit if it says otherwise.

Aida count Stitches per inch Approx. stitches per cm Typical strands Tapestry needle Notes
11-count 11 4.3 3 22 Large squares; good for children and anyone who finds small grids tiring
14-count 14 5.5 2 24 The usual starting fabric and the most common count in kits
16-count 16 6.3 2 24 or 26 A finer look once you are comfortable counting
18-count 18 7.1 1 or 2 26 or 28 Small, detailed stitches; good light helps

Getting started: cross stitch for beginners.

Sources

Needle, hook and yarn weight standards are based on the Craft Yarn Council hook and needle standards, its yarn weight system and crochet abbreviations. Manufacturers and older charts sometimes differ by a size; always check your tension or gauge before starting a garment.

Shop knitting and crochet and embroidery and cross stitch. Questions? Email craftiche.co.uk@gmail.com.