Yarn Weight Chart and Needle Size Guide
Yarn weight refers to the thickness of a strand of yarn, and it's one of the most important things to understand when choosing yarn for a project. The weight determines your gauge (stitches per inch), which needle or hook size to reach for, and what kinds of finished fabrics you can expect.
The Craft Yarn Council's Standard Yarn Weight System groups yarns into numbered categories from 0 (lace) to 7 (jumbo). The chart below covers the seven most common categories you'll find at Revolution Fibers, with recommended needle and hook sizes, typical gauge ranges, wraps per inch, and project suggestions for each.
Quick tip: These are guidelines, not rules. Always swatch and follow the gauge listed in your pattern. Your tension, needle material, and fiber choice all affect your results.
Yarn Weight Chart
| Yarn Weights | Suggested Needle Size | Suggested Hook Size | Stitches Per Inch | Wraps Per Inch (WPI) | Yards per 100g | Common Uses |
 |
0 - 2 US |
Steel: 6, 7, 8 Regular: B-1 |
Knit: 7-8 Crochet: 8-10.5 |
18+ | 650 - 875 | Lace Knitting, Crochet |
 |
1 - 3 US | B-1 to E-4 |
Knit: 6-7 Crochet: 5-8 |
16 | 440 - 525 | Socks & Lightweight Garments |
 |
3 - 5 US | E-4 to 7 |
Knit: 5-6 Crochet: 4-5 |
14 | 330 - 440 | Light Sweaters, Baby Items & Accessories |
 |
5 - 7 US | 7 to I-9 |
Knit: 5 Crochet: 3-4 |
13 | 260 - 328 | Sweaters, Scarves, Soft Hats |
 |
7 - 9 US | I-9 to K-10.5 |
Knit: 4-5 Crochet: 3-3.5 |
10-12 | 220 - 260 | Sweaters, Outdoor Wear, Blankets, Scarves, Mittens |
 |
9 - 11 US | K-10.5 to M-13 |
Knit: 4 Crochet: 2-3 |
10 | 120 - 140 | Rugs, Blankets, Warm Outerwear |
 |
11 & Up US | M-13 & Up |
Knit: 3-4 Crochet: 2 |
9 - 10 | 70 - 110 | Heavy Blankets, Sweaters, Rugs, Tapestries |
Understanding Each Yarn Weight
Lace Weight (Category 0)
Lace weight is the finest yarn commonly available. It produces delicate, open fabrics and is typically used for lace shawls, doilies, and lightweight wraps. Because the yarn is so thin, lace projects take longer to complete but use less yarn by weight. Expect 650 to 875 yards per 100 grams, which means a single skein can carry you through an entire shawl.
Needle size: US 0 to 2 (2.0 to 2.75 mm). Some lace knitters intentionally go up a needle size or two to open up the stitch pattern.
Fingering and Sock Weight (Category 1)
Fingering weight (also called sock weight) is the go-to for socks, lightweight shawls, and finely knit garments. It's thin enough for detailed colorwork and stitch patterns but sturdy enough to hold up in high-wear items like socks. Most fingering weight yarns give you 440 to 525 yards per 100 grams, making them an efficient choice when yardage matters.
Needle size: US 1 to 3 (2.25 to 3.25 mm). Sock knitters often use the lower end of this range for a tighter, more durable fabric.
Sport Weight (Category 2)
Sport weight sits between fingering and DK. It's a versatile middle ground that works well for baby garments, lightweight sweaters, and accessories where you want more drape than worsted but more substance than fingering. Sport weight yarns typically yield 330 to 440 yards per 100 grams.
Needle size: US 3 to 5 (3.25 to 3.75 mm).
DK Weight (Category 3)
DK stands for "double knitting," and it's one of the most popular yarn weights worldwide. It knits up faster than fingering or sport weight while still producing a fabric with good drape and detail. DK is a strong choice for sweaters, scarves, hats, and baby items. You'll typically get 260 to 328 yards per 100 grams.
Needle size: US 5 to 7 (3.75 to 4.5 mm).
Worsted Weight (Category 4)
Worsted weight is the most widely used yarn weight in North America. It's the default for many knitting and crochet patterns, and it's the weight most beginners learn on. Worsted produces a medium-weight fabric that works for nearly everything: sweaters, blankets, hats, scarves, mittens, and home goods. Most worsted yarns give you 220 to 260 yards per 100 grams.
Needle size: US 7 to 9 (4.5 to 5.5 mm). This range offers a good balance between speed and stitch definition.
Bulky Weight (Category 5)
Bulky weight yarn knits up quickly and creates thick, warm fabrics. It's a popular choice for winter accessories, cozy blankets, and chunky sweaters. The trade-off is less stitch definition compared to lighter weights, so simpler stitch patterns tend to show best. Expect 120 to 140 yards per 100 grams.
Needle size: US 9 to 11 (5.5 to 8.0 mm).
Super Bulky Weight (Category 6)
Super bulky yarn is the thickest standard weight. Projects work up fast, often in an evening or a weekend. It's ideal for statement blankets, oversized scarves, and quick-gift projects. Because the yarn is so thick, you'll use more by weight: expect only 70 to 110 yards per 100 grams. Simple patterns like garter stitch and stockinette show the yarn itself best.
Needle size: US 11 and up (8.0 mm and up).
How to Determine Yarn Weight
If you have yarn without a label, or you're working with handspun yarn, there are two reliable ways to identify the weight.
Wraps Per Inch (WPI)
Wrap the yarn snugly around a ruler, pencil, or WPI tool for one inch. Don't overlap the wraps or leave gaps. Count the number of wraps that fit in that inch, then check against the WPI column in the chart above.
- 18+ wraps: Lace weight
- 16 wraps: Fingering/sock weight
- 14 wraps: Sport weight
- 13 wraps: DK weight
- 10-12 wraps: Worsted weight
- 10 wraps: Bulky weight
- 9-10 wraps: Super bulky weight
Knitting a Gauge Swatch
Cast on 20 stitches using the needle size you'd normally choose for the yarn. Knit in stockinette for about 4 inches. Lay the swatch flat, measure 1 inch in the center (away from the edges), and count the stitches. Compare your stitches-per-inch count to the chart above to identify the weight category.
Yarn Weight and Needle Size: How They Work Together
The needle or hook sizes listed in the chart are starting points. Going up a size creates a looser, more draped fabric. Going down a size creates a tighter, denser fabric. Neither is wrong. It depends on what you're making.
For example, a sock knitter working fingering weight yarn might choose a US 1 needle for a snug, durable fabric. A shawl knitter using the same yarn might go up to a US 4 to open up the lace pattern. The yarn weight stays the same, but the needle choice shapes the finished result.
If you're following a pattern, always match the gauge listed in the pattern rather than the general recommendations in a chart. Your personal tension, the fiber content of the yarn, and even the needle material (wood, metal, bamboo) all influence your gauge.
Choosing the Right Yarn Weight for Your Project
Not sure which weight to use? Here are some practical starting points:
- Socks: Fingering weight. It's thin enough for a comfortable fit inside shoes and durable enough to hold up to wear.
- Shawls and wraps: Lace, fingering, or sport weight. Lighter weights create better drape and show off stitch patterns.
- Sweaters: DK or worsted weight. These are the most common sweater weights, offering a balance of warmth, structure, and stitch definition.
- Blankets: Worsted, bulky, or super bulky. Heavier weights make blankets faster to knit and more substantial to use.
- Baby items: Sport or DK weight. Light enough to be soft and comfortable, but substantial enough to hold its shape after washing.
- Hats, mittens, scarves: Worsted or bulky weight. Quick to make and warm to wear.
- Quick gifts: Bulky or super bulky. Thick yarn on large needles means finished projects in hours, not weeks.
Frequently Asked Questions
What is the most common yarn weight?
Worsted weight (category 4) is the most widely used yarn weight in North America. It's the default for many patterns, it's widely available, and it works for a broad range of projects from sweaters to blankets. If you're new to knitting or crochet, worsted weight is a reliable place to start.
Can I substitute one yarn weight for another?
You can, but it will change the finished size, drape, and gauge of your project. If you substitute a heavier yarn, the finished item will be larger and thicker. If you substitute a lighter yarn, it will be smaller and thinner. When substituting, always knit a gauge swatch and adjust your needle size to match the pattern's stated gauge as closely as possible.
What does "ply" mean, and is it the same as yarn weight?
Ply refers to the number of individual strands twisted together to make the yarn. A 2-ply yarn has two strands; a 4-ply has four. However, ply does not reliably indicate weight. A bulky single-ply yarn can be thicker than a fine 4-ply. In some countries (especially Australia and the UK), terms like "4-ply" and "8-ply" are used as weight names, but in the U.S., it's more reliable to go by the Craft Yarn Council weight categories or by checking the gauge and WPI.
What is WPI and why does it matter?
WPI stands for wraps per inch. It's a measurement of how many times a strand of yarn wraps around a ruler in one inch, and it's the most reliable way to determine yarn weight when you don't have a label. WPI is especially useful for handspinners evaluating their own yarn and for knitters working with unlabeled yarn from their stash.
What needle size should a beginner start with?
Most beginners do well starting with US 7 or US 8 needles (4.5 to 5.0 mm) paired with worsted weight yarn. The stitches are large enough to see clearly, the yarn moves at a manageable pace, and the needle size is comfortable to hold. From there, you can move to finer or heavier yarns as your skills develop.
Do I need different needles for different yarn weights?
Yes. Each yarn weight has a recommended needle size range that produces a balanced fabric. Using needles that are too small for the yarn creates stiff, tight fabric. Using needles that are too large creates loose, floppy fabric. Most knitters build a needle collection over time, or invest in an interchangeable knitting needle set that covers a range of sizes in one kit.
Looking for yarn in a specific weight? Browse our full yarn collection and filter by weight to find the right match for your project. Need help choosing? Reach out to our team and we'll point you in the right direction.