There are a few types of yarn descriptions in use today:
North American or The Standard Yarn Weight System, Tex, and Metric or English Worsted
North American yarn descriptions are used the most and though they are approximate and less precise than the other two systems, they tend to be more comfortable to use for many involved in the wool crafts.
The numbers will vary somewhat depending on the type of fiber used to make the yarn. The yarn itself may be 2 or more strands also called plies.
The photos below show what we mean by "types" of fibers used. The heavier the fiber the heavier the yarn and it may NOT look to your eye to be a certain weight, but will calculate to the number of yards per pound.
The Standard Yarn Weight System
Categories of yarn, wraps per inch or WPI, gauge ranges, and recommended needle and hook sizes will give you general starting place.
Remember: Many manufacturers have their own standard weights of yarn.
Please note: that a gauge range is difficult to determine, and following the gauge stated in your pattern is the best way to insure success. For instance- One knitter almost always goes down 2 needle sizes from the suggested in the pattern. She is a loose knitter and knows 2 sizes smaller is a good starting point. Learning to gauge saves time and head aches.
A side note: Steel crochet hooks are sized differently from regular crochet hooks—the higher the number, the smaller the hook, which is the reverse of regular hook sizes.
Chunky Is heavier than Bulky, Can be roving
Knitting = 6–11 stitches per 4 inches on an 8 mm or 11 US needle or larger
Crochet = 5 -9 stitches per inch on an 9 mm or M13 US needle or larger
Bulky Weight Less than 8 wraps per inch - 400 to 700 yards per pound
Knitting = 12- 15 stitches per 4 inches on an 5.5 - 8 mm or 9 - 11 US needle
Crochet = 8-11 stitches per inch on an 6.5— 9 mm or K–10 1/2 to M–13 US needle
Aran Weight 6 to 10 wraps per inch - 700 to 1000 yards per pound
Knitting = 16-20 stitches per 4 inches on an 4.5 - 5.5 mm or 7- 9 US needle
Crochet = 11 - 14 stitches per inch on an 5.5 - 6.5 mm or I–9 to K–10 1/2 US needle
Worsted Weight: 10 to 12 wraps per inch - 900 to 1100 yards per pound;
Knitting = 16-20 stitches per 4 inches on an 4.5 - 5.5 mm or 7 - 9 US needle
Crochet = 12 -17 stitches per inch on an 5.5 - 6.5 mm or I–9 to K–10 1/2 US needle
Double Knitting (DK): 12 to 18 wraps per inch - 1000 to 1400 yards per pound;
Knitting = 21 -24 stitches per 4 inches on an 3.75 - 4.5 mm or 5- 7 US needle
Crochet = 11 - 14 stitches per inch on an 4.5- 5.5 mm or 7 to I–9 US needle
Sport Weight: 18 to 24 wraps per inch - 1300 to 1800 yards per pound
Knitting = 23 -26 stitches per 4 inches on an 3.25 - 3.75 mm or 3 - 5 US needle
Crochet = 16 - 20 stitches per inch on an 3.5 - 4.5 mm or E4 - 7 US needle
Fingering:24 to 30 wraps per inch - 1800 to 2400 yards per pound
Knitting = 27 -32 stitches per 4 inches on an 2.25 - 3.25 mm or 1 -3 US needle
Crochet = 21 - 32 stitches per inch on an 2.25 - 3.5 mm or B1- E4 US needle
Baby:30 to 36 wraps per inch - 2400 to 3000 yards per pound;
Lace Weight:36 to 40 wraps per inch - 3000 to 6000 yards per pound
Lace weight yarns are most often knitted or crocheted on larger needles/ hooks to create the lacy patterns.
Cobweb:40 or more wraps per inch - 6000 or more yards per pound; and
Zephyr weight yarn is finer than Cobweb
You will find spinning weights are a bit different due to the many weights
Wraps Per Inch
What is it and how do you come up with a number?
Get yourself a ruler, or buy a WPI measure if you want
Take your yarn and wrap the yarn around ruler for 2 inches
DO NOT wrap too tightly or too loosely- just a nice even wrap
Slide the yarn strands so they are touching- not overlapping
Count the number of wraps
Divide that number by 2
This is your wraps per inch!
Worsted Weight Yarn
Worsted wool is nothing to do with worsted weight yarn. Worsted wool is wool which is carded and then combed so that all the fibers are aligned in a parallel manner. Woolen measure or also called
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