Guide
Yarn Weight Chart: Numbers 0 to 7, Names and Hook Sizes
By Notion Creative Art · Updated
Yarn weight describes how thick a strand of yarn is, not how heavy the ball feels. A yarn weight chart puts every yarn on a scale from 0 (lace) to 7 (jumbo), so you can see at a glance what hook it needs and what it is good for. This guide explains the numbers, the common names, the UK and US differences, and how to swap one yarn for another without ruining a project.
What yarn weight really means
Yarn weight is the thickness of the strand. A thin yarn makes a light, drapey fabric. A thick yarn makes a dense, warm fabric and works up fast. The same pattern in two different weights gives two very different results, which is why a pattern always names the weight it was written for.
The standard system numbers the weights from 0 to 7. Many labels print the number inside a small ball-of-yarn symbol, and the next section shows how those numbers line up with names.
The yarn weight chart, 0 to 7
| No. | Category | Common names | Typical hook |
|---|---|---|---|
| 0 | Lace | Lace, thread, fingering (very fine) | 1.6 to 2.25 mm |
| 1 | Super fine | Fingering, sock, baby | 2.25 to 3.5 mm |
| 2 | Fine | Sport, baby | 3.5 to 4.5 mm |
| 3 | Light | DK, light worsted | 4.5 to 5.5 mm |
| 4 | Medium | Worsted, aran, afghan | 5.5 to 6.5 mm |
| 5 | Bulky | Chunky, craft, rug | 6.5 to 9 mm |
| 6 | Super bulky | Super chunky, roving | 9 to 15 mm |
| 7 | Jumbo | Jumbo, roving | 15 mm and larger |
The hook ranges above are the sizes usually printed on yarn labels. They are a starting point. Our crochet hook sizes chart lists metric, US and UK sizes side by side.
What each weight is good for
- Lace and super fine (0 and 1): fine shawls, doilies, lightweight baby items and very small amigurumi.
- Fine (2): baby clothes, light cardigans and small toys with detailed shaping.
- Light (3): garments, accessories and small to medium amigurumi. DK is a popular all-rounder.
- Medium (4): blankets, hats, scarves and many amigurumi. It is the weight most beginners start with because stitches are easy to see.
- Bulky (5): quick hats, cozy blankets, baskets and large, soft toys.
- Super bulky and jumbo (6 and 7): chunky throws, rugs and statement pieces, often worked with a very large hook.
Which weight for amigurumi
Most amigurumi patterns use a light or medium yarn (DK or worsted) with a hook a size or two smaller than the label suggests. The tighter stitches keep the stuffing from showing through. Thinner yarn makes a smaller, more detailed toy, and thicker yarn makes a bigger, faster one.
Fiber and texture matter just as much as weight. Our guide to the best yarn for amigurumi covers smooth cotton, acrylic and other choices, and our no-sew amigurumi patterns list the yarn each design uses.
UK versus US yarn names
Yarn names differ between countries, and the same word can mean slightly different things. The matches below are close, not exact, so treat them as a guide and check the label.
| UK name | Closest US idea | Number |
|---|---|---|
| 2-ply or 3-ply | Lace | 0 |
| 4-ply | Fingering or sock | 1 |
| Sport (less common) | Sport | 2 |
| DK (double knitting) | Light worsted | 3 |
| Aran | Worsted (close, not identical) | 4 |
| Chunky | Bulky | 5 |
| Super chunky | Super bulky | 6 |
Worsted versus DK: a DK yarn is thinner than worsted. Using DK where a pattern asks for worsted gives a smaller, looser piece unless you adjust the hook and check gauge.
Yarn weight is not ball weight
Beginners often mix up two different "weights." Yarn weight is the thickness of the strand. Ball weight is how many grams or ounces are in the ball, for example 50 g or 100 g. A 100 g ball of lace yarn and a 100 g ball of chunky yarn weigh the same, but the lace ball holds far more length.
Length is what you actually need to finish a project, so patterns list yardage or meters. Our guide to how to read yarn labels explains the length, weight and care symbols on a band.
How to substitute one yarn for another
- Match the weight category first. Replace a worsted with another worsted, not with a DK.
- Compare yardage per 100 g. If the new yarn has about the same length for the same weight, it is likely a similar thickness and density.
- Check the fiber. Cotton has no stretch, wool is springy and acrylic is light and soft, so the finished piece will behave differently.
- Buy enough yarn. Use the pattern's total yardage and divide by the yardage per ball. Round up, and buy one extra if you can.
- Make a swatch with the hook the pattern suggests, then measure it. Our gauge swatch guide shows how.
- Adjust the hook size up or down until your swatch matches the pattern gauge.
Common problems and fixes
| What you see | Why | What to do |
|---|---|---|
| The finished piece is smaller than the pattern says | The yarn is thinner than the one used, or your tension is tight | Check the weight on the label, swatch, and go up a hook size |
| Fabric feels floppy or has big gaps | The hook is too large for the yarn, or the yarn is too thin | Try a smaller hook or a thicker yarn in the same category |
| Stuffing shows through amigurumi | Stitches are too loose for the yarn | Use a hook one or two sizes smaller than the label suggests |
| The pattern runs out of yarn | The substitute has less yardage per ball | Compare yardage per 100 g before buying and buy extra |
Practice and next steps
Pick two yarns from different weight categories and crochet a small swatch of each with the same stitch. Put them side by side and feel how thickness changes the fabric. If you are choosing a first project, our crochet patterns for beginners list the yarn and skill level for every design.
Quick answers
- What is the most common yarn weight?
- Medium (worsted, number 4) and light (DK, number 3) are among the most widely used weights for crochet. They suit blankets, garments and many amigurumi toys. They are also easy to find in many colors and fibers.
- Is DK the same as worsted?
- No. DK is thinner than worsted. DK is close to the US light worsted idea (number 3), while worsted is number 4. Swapping them changes your gauge, so make a swatch first.
- Is aran the same as worsted?
- They are close, but not always identical. UK aran and US worsted both sit around number 4, and many patterns treat them as interchangeable. Check the label and swatch to be sure.
- Can I use a different hook size than the label says?
- Yes. The label range is only a suggestion. Amigurumi often uses a smaller hook for tight stitches, and drapey fabrics may use a larger one. Pick the hook that gives the right gauge for your project.
- How do I find the weight of a yarn with no label?
- Wrap the yarn around a ruler for one inch or two centimeters and count the wraps, then compare to a wraps-per-inch chart. You can also crochet a swatch and compare it to a labeled yarn. These are rough methods, so treat the result as an estimate.
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