Worsted (#4) and DK (#3) sit one weight category apart but produce visibly different fabric. Here's when to pick each, with hook sizes, gauge, and project examples.
Worsted-weight yarn (Craft Yarn Council #4) is medium-weight, paired with a 5–5.5mm (US H/I) hook, and gives roughly 11–14 single crochets per 4 inches. DK yarn (#3) is one step lighter, paired with a 4–4.5mm (US G/7) hook, gauging at 12–17 sc per 4 inches. Use worsted for amigurumi, blankets, beginner projects, and anything where stitch definition + speed matter. Use DK for finer amigurumi, baby items, and lightweight garments where drape matters. To substitute worsted with DK: use the next-larger hook and expect ~10% smaller finished size; substitute DK with worsted using the next-smaller hook and expect ~10% larger size.
| Property | Worsted (#4) | DK (#3) |
|---|---|---|
| CYC weight number | 4 (Medium) | 3 (Light) |
| US term | Worsted / Aran | DK / Light Worsted |
| UK term | Aran | DK |
| Recommended hook | 5–5.5mm (H/I) | 4–4.5mm (G/7) |
| Gauge (sc/4") | 11–14 | 12–17 |
| Yards per 100g | ~190–220 | ~250–290 |
| Best for | Amigurumi, blankets, hats, scarves | Baby items, fine amigurumi, lightweight garments |
| Drape | Substantial, holds shape | Lighter, more flowy |
| Beginner-friendly | Yes — easiest | Slightly trickier — finer stitches |
| Speed | Faster (bigger stitches) | Slower (smaller stitches) |
Worsted weight (#4) is the default for a reason. It's the most-used yarn weight in the US crochet community: the stitches are large enough that beginners can see what they're doing, the gauge is forgiving, and most patterns assume worsted unless they say otherwise. Reach for worsted when you're making amigurumi (with a 4–4.5mm hook for tighter fabric), blankets, hats, scarves, and anything that needs to hold its shape. Brands like Lion Brand Vanna's Choice, Red Heart Super Saver, and Paintbox Cotton Aran all sit firmly in the worsted category.
DK (#3) is one step lighter and produces visibly more refined stitches. Use it when you want finer detail (mini amigurumi, keychain plushies), when you need drape (baby blankets, lightweight garments, lacy cardigans), or when working with cotton — DK cotton like Paintbox Cotton DK has crisp stitch definition that's harder to get with worsted. The downside: DK projects take longer because the stitches are smaller.
Cross-substituting worsted and DK is common but not transparent. Going worsted → DK: use the next hook size up (a worsted 5mm pattern → 4.5mm with DK), and expect the finished size to come out ~10% smaller. Going DK → worsted: drop the hook size down by 0.5mm, and expect ~10% larger output. Always swatch before committing — gauge differences compound across rows.
Is DK lighter than worsted?
Yes — DK is Craft Yarn Council weight #3, worsted is #4. DK is lighter by roughly 20–30% in linear yardage per gram, and the resulting stitches are visibly smaller.
Can I use DK in a worsted pattern?
Yes, with adjustments. Use a hook size larger than the pattern's recommendation (e.g. 5.5mm if pattern said 5mm) and the finished item will come out close to original size. Some drape will differ — DK is lighter.
What hook size for DK yarn?
A 4mm (US G/6) hook is the standard. For amigurumi in DK, drop to 3.5mm (E/4) so the fabric is tight enough that polyfill doesn't show through.
Is worsted the same as Aran?
In US terminology, worsted and Aran are both #4 weight and largely interchangeable. In UK terminology, Aran specifically means the heavier end of #4 — closer to a US heavy-worsted.
Which is better for amigurumi: worsted or DK?
Worsted is more common — it's faster and easier for beginners. DK gives finer detail and is preferred for keychain-sized makes or when stitch definition really matters. Both work well; pick based on the finished size you want.
How many stitches per inch does worsted give?
Worsted with a 5mm hook gives roughly 3–3.5 single crochets per inch (or 11–14 per 4 inches). With a smaller hook for amigurumi, expect closer to 4 sc per inch.