Reference & converters
Key takeaway: Use these charts when a ball band or pattern disagrees with your notions—for example, a US 8 knitting needle is 5.0 mm (UK 6) on the CYC-aligned converter.
Cross-Stitch Fabric (Aida Count) Calculator
Convert stitch counts and Aida count into design size and fabric cut size with margins.
Needle & Hook Size Converter
Convert knitting needle and crochet hook sizes between US, UK, and metric millimeters.
CYC yarn weight standards
Categories 0–7 with gauges and sources.
Quilt & mattress sizes
Standard blanket, quilt, and mattress dimensions.
What belongs in Reference
Reference pages hold standards and conversion tables—not project estimators. Start with the CYC yarn weight standards when substituting yarn or reading a ball-band icon. Use the needle & hook converter for US / metric / UK labels (metric millimeters are the reliable cross-brand measure; UK labels are approximate and not published by CYC). Cross-stitchers should open the Aida fabric calculator. Quilters comparing tops to mattresses can use quilt & mattress sizes.
How to read CYC yarn categories
Craft Yarn Council categories run from 0 (Lace) through 7 (Jumbo). Category 4 (Medium / worsted) is the default in most FiberCalc yarn tools. Match the symbol on the ball band to the “#” column, then confirm the published knit or crochet gauge range. Wraps-per-inch (WPI) helps when a leftover cake has no label—see the CYC how to measure WPI page alongside our table. Lace (category 0) crochet gauge on CYC is listed in double crochets, not single crochet.
Worked example: needle conversion
A US pattern calls for size 8 needles and your metric set is unmarked by US number. On the converter, US 8 maps to 5.0 mm (commonly UK 6). Always swatch: letter/number systems vary slightly by brand, which is why CYC emphasizes the millimeter marking on the package.
Worked example: Aida cut size
A chart 140 stitches wide on 14-count Aida is 140 ÷ 14 = 10″ of design width. With 3″ margins on each side, cut fabric about 16″ wide. The Aida calculator also handles height and “over two” linen equivalents.
Common mistakes
- Trusting “DK” or “worsted” brand names without checking the CYC category icon and gauge.
- Mixing US letter hooks with steel-hook numbering (steel sizes run the opposite direction).
- Using mattress dimensions as quilt-top sizes without adding drop, tuck, or border ease.
- Treating FiberCalc yards-per-100 g midpoints as CYC standards—they are planning heuristics for substitution math.
Related hubs and guides
Project calculators live under knitting & crochet, sewing, and quilting. Guides that use these charts: yarn substitution basics, hook size conversion chart, and what size Aida for cross stitch. Source policy and density factors: Methodology.