Yarn Weight Chart and Needle Size Guide

Revolution Fibers reference guide

Yarn Weight Chart & Needle Size Guide

Compare standard yarn weights, knitting needle and crochet hook sizes, gauge ranges, wraps per inch, common yarn names, and practical project uses. The guide also shows how to identify unlabeled yarn and measure finished handspun without treating one number as the whole answer.

View the yarn weight chart Measure yarn with WPI Download the printable chart
Infographic showing wraps per inch, a gauge swatch, standard yarn weight categories 0 through 7, knitting needles, and a crochet hook.

Categories, gauge, WPI, needles, and hooks

Standard yarn weight chart

Yarn weight describes the approximate thickness of a yarn strand. The Craft Yarn Council's numbered system groups yarn from Category 0 Lace through Category 7 Jumbo and pairs each category with common gauge and tool-size starting ranges.

Common names such as fingering, sport, DK, worsted, and chunky are useful, but brands do not always use them in exactly the same way. When a precise fit matters, compare the category, metric tool size, pattern gauge, and finished swatch together.

0Lace
1Super Fine
2Fine
3Light
4Medium
5Bulky
6Super Bulky
7Jumbo
Swipe or scroll horizontally on a small screen to compare every column.
Category Common terms Approx. WPI Knit gauge Suggested needles Crochet gauge Suggested hooks Common uses
0Lace lace, thread 30-40+ 33-40 sts / 4 in* 1.5-2.25 mm | US 000-1 32-42 dc / 4 in* Steel 1.4-1.6 mm or regular 2.25 mm | US steel 6-8 or B-1 Open lace, fine wraps, delicate crochet, lightweight layering
1Super Fine fingering, sock, baby 14-30 27-32 sts / 4 in 2.25-3.25 mm | US 1-3 21-32 sc / 4 in 2.25-3.5 mm | US B-1-E-4 Socks, colorwork, fine accessories, lightweight garments
2Fine sport, baby 12-18 23-26 sts / 4 in 3.25-3.75 mm | US 3-5 16-20 sc / 4 in 3.5-4.5 mm | US E-4-7 Light sweaters, baby items, accessories, warm-weather layers
3Light DK, light worsted 11-15 21-24 sts / 4 in 3.75-4.5 mm | US 5-7 12-17 sc / 4 in 4.5-5.5 mm | US 7-I-9 Sweaters, scarves, hats, baby garments, versatile accessories
4Medium worsted, afghan, aran 9-12 16-20 sts / 4 in 4.5-5.5 mm | US 7-9 11-14 sc / 4 in 5.5-6.5 mm | US I-9-K-10 1/2 Sweaters, blankets, hats, mittens, scarves, home goods
5Bulky bulky, chunky, rug 6-9 12-15 sts / 4 in 5.5-8 mm | US 9-11 8-11 sc / 4 in 6.5-9 mm | US K-10 1/2-M-13 Warm accessories, blankets, outer layers, quick projects
6Super Bulky super bulky, roving-style 5-6 7-11 sts / 4 in 8-12.75 mm | US 11-17 7-9 sc / 4 in 9-15 mm | US M-13-Q Heavy blankets, oversized accessories, baskets, fast gifts
7Jumbo jumbo, very thick roving-style 1-4 6 sts or fewer / 4 in 12.75 mm and larger | US 17+ 6 sc or fewer / 4 in 15 mm and larger | US Q+ Large-scale blankets, rugs, baskets, arm or hand projects

Gauge notes: Knitting gauge is measured in stockinette over 4 inches. Crochet gauge is measured in single crochet over 4 inches, except Category 0, where the published guideline uses double crochet. Lace is often worked on larger tools for open fabric, so pattern gauge matters more than a general chart.

WPI notes: WPI ranges overlap. That is expected. Wrap without stretching or compressing, measure several places, and swatch before beginning the project.

Browse yarn by weight See needles & crochet hooks Open the printable guide

A practical estimate, not a verdict

Yarn Weight Finder

Enter one measurement you know. The finder returns every standard category whose published range includes that number. Overlapping results are normal and useful: they tell you when the yarn sits near a category boundary.

For Category 0 crochet, the published gauge is double crochet. Categories 1-7 use single crochet. Results are starting points and should be confirmed with a swatch.

Your result will appear here.

WPI is usually the best first estimate for unlabeled or finished handspun yarn. Gauge can support the estimate when you already have a representative swatch.

Use more than one clue

Compare WPI, gauge, fiber, twist, ply structure, bloom, and the fabric you want. No single number describes every part of a yarn.

Wash the swatch

Many fibers relax, bloom, lengthen, or change hand after washing. Judge the finished fabric after the care process the project will receive.

Pattern gauge wins

When following a pattern, use the chart to choose a starting tool size, then adjust until the washed swatch matches the pattern gauge and fabric.

For unlabeled yarn and finished handspun

How to measure yarn weight with WPI

WPI means wraps per inch: the number of relaxed, side-by-side yarn wraps that fit inside one measured inch. It is a practical way to estimate the category of mystery yarn, stash yarn without a label, or handspun after finishing.

For handspun, measure the yarn in the form you plan to use. If the final yarn is plied, measure after plying, setting the twist, drying fully, and letting the skein relax.

Instructional diagram showing how to measure wraps per inch with yarn wraps touching, not overlapping, and not stretched.

What a good measurement looks like

The wraps touch without crossing. The strand keeps its natural shape. You count complete wraps inside one inch, then repeat the process in two or three other areas.

For uneven handspun: record the range and average. A skein that reads 10, 11, and 12 WPI is better described as a range than forced into one exact number.

1

Prepare the yarn

Use the finished yarn whenever possible. Let washed yarn dry and relax completely.

2

Wrap gently

Use a ruler, pencil, dowel, or WPI gauge. Do not pull the yarn thinner.

3

Count one inch

Place wraps side by side without gaps or overlap. Count complete wraps within the inch.

4

Repeat

Measure several areas, especially when the yarn is textured or varies in thickness.

5

Compare and swatch

Use the WPI range as an estimate, then make the fabric and wash it before deciding.

WPI can help you

  • Estimate the category of unlabeled or handspun yarn.
  • Choose a reasonable needle or hook starting range.
  • Compare a mystery yarn with a pattern yarn.
  • Record a skein for future project planning.
  • Notice when a yarn sits near a category boundary.

WPI cannot tell you everything

  • It does not replace a washed gauge swatch.
  • It does not measure softness, drape, elasticity, or durability.
  • It does not make all yarns in one category interchangeable.
  • It does not account for the full effect of fiber and construction.
  • For weaving, it does not replace sett calculations and sampling.

From singles to project-ready yarn

Still finishing the skein?

Find bobbins, flyers, lazy kates, niddy noddies, skeinwinders, and ball winders for the steps between freshly spun singles and yarn that is ready to measure, store, or use.

See plying & finishing tools

What the categories feel like in practice

Understanding each yarn weight

The numbered system is useful because it creates a shared starting language. The finished fabric still depends on fiber, spin, ply, twist, tool size, stitch or weave structure, and finishing.

0

Category 0

Lace weight

Common terms: lace, thread

Approx. WPI: 30-40+
Knitting needles: 1.5-2.25 mm | US 000-1
Crochet hooks: Steel 1.4-1.6 mm or regular 2.25 mm | US steel 6-8 or B-1

Often used for: Open lace, fine wraps, delicate crochet, lightweight layering.

See lace weight yarn
1

Category 1

Super Fine weight

Common terms: fingering, sock, baby

Approx. WPI: 14-30
Knitting needles: 2.25-3.25 mm | US 1-3
Crochet hooks: 2.25-3.5 mm | US B-1-E-4

Often used for: Socks, colorwork, fine accessories, lightweight garments.

See fingering weight yarn
2

Category 2

Fine weight

Common terms: sport, baby

Approx. WPI: 12-18
Knitting needles: 3.25-3.75 mm | US 3-5
Crochet hooks: 3.5-4.5 mm | US E-4-7

Often used for: Light sweaters, baby items, accessories, warm-weather layers.

See sport and DK yarn
3

Category 3

Light weight

Common terms: DK, light worsted

Approx. WPI: 11-15
Knitting needles: 3.75-4.5 mm | US 5-7
Crochet hooks: 4.5-5.5 mm | US 7-I-9

Often used for: Sweaters, scarves, hats, baby garments, versatile accessories.

See sport and DK yarn
4

Category 4

Medium weight

Common terms: worsted, afghan, aran

Approx. WPI: 9-12
Knitting needles: 4.5-5.5 mm | US 7-9
Crochet hooks: 5.5-6.5 mm | US I-9-K-10 1/2

Often used for: Sweaters, blankets, hats, mittens, scarves, home goods.

See worsted weight yarn
5

Category 5

Bulky weight

Common terms: bulky, chunky, rug

Approx. WPI: 6-9
Knitting needles: 5.5-8 mm | US 9-11
Crochet hooks: 6.5-9 mm | US K-10 1/2-M-13

Often used for: Warm accessories, blankets, outer layers, quick projects.

See bulky weight yarn
6

Category 6

Super Bulky weight

Common terms: super bulky, roving-style

Approx. WPI: 5-6
Knitting needles: 8-12.75 mm | US 11-17
Crochet hooks: 9-15 mm | US M-13-Q

Often used for: Heavy blankets, oversized accessories, baskets, fast gifts.

See super bulky yarn
7

Category 7

Jumbo weight

Common terms: jumbo, very thick roving-style

Approx. WPI: 1-4
Knitting needles: 12.75 mm and larger | US 17+
Crochet hooks: 15 mm and larger | US Q+

Often used for: Large-scale blankets, rugs, baskets, arm or hand projects.

Browse jumbo yarn (roving)

Why two yarns at the same weight can behave differently

Thickness is only one part of the fabric

Wool and elastic fibers

Wool often has more recovery than plant fibers and may bloom after washing. Breed, preparation, twist, and finishing change the result.

Cotton and linen

Plant fibers are often less elastic and can create more drape or weight. The same gauge may feel different from wool in the hand.

Silk and dense fibers

Silk can feel smooth, fluid, and comparatively dense. Yardage per 100 grams may differ from a lofty wool yarn of similar thickness.

Singles, plies, and halo

A smooth, tightly plied yarn packs differently from a lofty single or haloed yarn. Visual diameter and fabric behavior are not always the same.

Why yards per 100g varies

Yardage is not standardized by weight category. Fiber density, twist, ply, loft, and construction can change how many yards fit into 100 grams. Use the label when available and treat normalized yardage as supporting information.

A useful label calculation

To normalize a label for comparison, divide the listed yards by the listed grams, then multiply by 100. This gives yards per 100 grams. It does not independently determine the yarn category.

A note for weavers

WPI can help describe thickness, but WPI is not sett. Sett also depends on weave structure, yarn behavior, intended drape, and finishing. Sample before winding the full warp.

Metric and U.S. sizes

Knitting needle and crochet hook conversions

Metric sizing measures the tool diameter and is the clearest comparison when brands use different U.S. labels. Use these conversions as a reference, then follow the pattern's stated millimeter size and gauge whenever possible.

Knitting needle conversion chart
Metric U.S.
1.50 mm 000
1.75 mm 00
2.00 mm 0
2.25 mm 1
2.75 mm 2
3.00 mm No exact CYC U.S. equivalent
3.125-3.25 mm 3
3.50 mm 4
3.75 mm 5
4.00-4.25 mm 6
4.50 mm 7
5.00 mm 8
5.25-5.50 mm 9
5.75-6.00 mm 10
6.50 mm 10 1/2
7.00 mm No exact CYC U.S. equivalent
8.00 mm 11
9.00 mm 13
10.00 mm 15
12.50-12.75 mm 17
15.00 mm 19
19.00 mm 35
25.00 mm 50
35.00 mm 70
Crochet hook conversion chart
Metric U.S.
2.25 mm B-1
2.50 mm No exact CYC U.S. equivalent
2.75 mm C-2
3.125 mm D
3.25 mm D-3
3.50 mm E-4
3.75 mm F-5
4.00 mm G-6
4.25 mm G
4.50 mm 7
5.00 mm H-8
5.25 mm I
5.50 mm I-9
5.75 mm J
6.00 mm J-10
6.50 mm K-10 1/2
7.00 mm No exact CYC U.S. equivalent
8.00 mm L-11
9.00 mm M/N-13
10.00 mm N/P-15
11.50 mm P-16
12.00 mm No exact CYC U.S. equivalent
15.00 mm P/Q
15.75-16.00 mm Q
19.00 mm S
25.00 mm T/U/X
30.00 mm T/X

From chart to project

Choosing a yarn weight for your project

Socks

Fingering or sock yarn is common because it can create a fine fabric that fits inside shoes. Fiber blend, twist, and gauge affect durability.

Shawls and wraps

Lace through sport yarn often supports drape and stitch detail. DK and heavier yarns can create warmer, more substantial wraps.

Sweaters

Fingering through worsted are common choices. Lighter yarns create a finer fabric; heavier yarns usually build warmth and structure faster.

Blankets and home goods

Worsted through super bulky are common for blankets. Choose for the desired weight, washability, stitch definition, and time commitment.

Baby items

Sport and DK are common because they balance softness, lightness, and structure. Care instructions and fiber suitability matter as much as weight.

Hats, mitts, and scarves

DK through bulky often works well for warm accessories, but the intended fit and fabric should determine the final gauge.

Quick gifts

Bulky and super bulky yarn can reduce stitch count, but project size, pattern, and finishing still determine how quickly it works up.

Weaving

Yarn weight offers a starting description. Use WPI, manufacturer information, weave structure, sett guidance, and a sample to plan the cloth.

Handspun-led projects

Simple shapes and textures let the yarn remain visible. Cowls, hats, mitts, woven scarves, small shawls, and accent sections are practical starting points.

Common questions and useful distinctions

Yarn weight FAQ

What is yarn weight?

Yarn weight describes the approximate thickness of the yarn strand, not the number on a scale. The category helps you choose a starting needle or hook size and anticipate the kind of fabric the yarn may create.

What is the most common yarn weight?

Medium or Category 4 yarn - often called worsted, afghan, or aran - is widely used in North America. It is common in sweaters, hats, blankets, scarves, mittens, and beginner projects.

Can I substitute one yarn in the same category for another?

Sometimes, but category alone does not guarantee a match. Compare the pattern gauge, fiber, construction, elasticity, drape, and yardage. Make and wash a swatch before committing to the project.

Is ply the same as yarn weight?

No. Ply tells you how many strands were combined. Weight describes the approximate thickness of the finished yarn. A fine multi-ply yarn can be thinner than a bulky single.

What does WPI mean?

WPI means wraps per inch. It estimates thickness by counting how many relaxed, side-by-side wraps fit within one inch. Because wrapping tension changes the result, measure more than one area and confirm with a swatch.

Should I measure handspun before or after washing?

For final project planning, measure the yarn in the state you will use it. That usually means after plying, setting the twist, drying fully, and letting the skein relax. Some fibers and yarn structures bloom or settle after washing.

What if my handspun gives several WPI readings?

Record the range and average rather than forcing the skein into one number. Then swatch a representative section. Variable yarn often works beautifully in simple textures, woven accents, stripes, hats, cowls, and small accessories.

Does WPI tell me which needle or hook to use?

It gives you a starting range. The right tool depends on the fabric you want and the gauge required by the pattern. A lace shawl and a sock can use yarn of similar thickness with very different tool sizes.

Why do yarn-weight charts disagree?

Yarn categories overlap, brands use common names differently, and WPI varies with wrapping tension. Fiber, halo, twist, ply structure, and bloom can also change how thick a yarn appears or behaves.

Why is metric sizing helpful?

Metric sizing is the tool diameter in millimeters. U.S. letters and numbers are useful shorthand, but some manufacturers map them differently. When precision matters, compare the millimeter size.

Is WPI the same as weaving sett?

No. WPI can help describe yarn thickness, but sett is the number of warp ends per inch. Sett also depends on weave structure, yarn behavior, and the cloth you want. Weavers should sample before committing the full warp.

Why is there no universal yards-per-100g range in the chart?

Yardage depends on fiber density, twist, ply structure, loft, and manufacturing method. Two yarns with similar thickness can have very different yards per 100 grams. Use yardage as supporting evidence, not a standalone yarn-weight test.

Method and review note: Standard category names, gauge ranges, and recommended knitting needle and crochet hook ranges were checked against the Craft Yarn Council's public standards. WPI ranges were checked against its WPI guide. The interpretation, mystery-yarn workflow, handspun guidance, weaving notes, and project-planning explanations were written for Revolution Fibers customers. Last reviewed July 2026.

A practical next step

Need a second opinion on your yarn?

Send the fiber, WPI range, approximate yardage, planned craft, and the fabric you want. The Revolution Fibers team can help you think through a useful starting point.

Ask Revolution Fibers
Browse yarn by weightCompare fibers, colors, constructions, and standard weight filters. See knitting needlesFind fixed, straight, double-pointed, and interchangeable options. See crochet hooksCompare individual hooks and complete sets by size and material.