​UPDATED 11/2016

A Place for Knitting Machine Enthusiasts

Be INFORMED!!  Go to this site:  GIRLZ2point0.com   Written by a Female for Females and BE HEARD

Yarn Weight Systems ~ Measurements

This section is about how yarn is weighted, meaning how thick it is and the different systems used.  It is important, because certain types of yarns work with certain machine guages and others will not, and worl well with certain items you are knitting.  It is the first building block when making something  Yarn information is a really tough subject and can be very confusing because certain terms such as the term "Worsted" can mean different things to different people or different cultures.  Certain terms can only be used with certain fibers, other terms can be interchangeable and yarn counts as far as plies (how many yarns are twisted together) can be different numbers in different countries and also with different yarn fibers.   Sheesh!  Is your head spinning yet? I will try to explain what I know with my limited knowledge and experience.  This area, textiles, people go to school for in order to major in the subject and there is volumes of information on this subject, so if something is amiss with my information on this page any help in correcting it would be appreciated.  I would encourage you to download the  "Convertible Yarn Chart"  in the Downloads Section.

Basically, yarn thickness or fineness is the gauge or circumference “around” the yarn strand.  There is a standard to follow by the  "Craft Yarn Council"   here  in the USA to make things easier and they have a  "Standard Yarn Weight System".  For you to be able to judge what yarns you want to use for your knitting machines and projects directly relates to how thick your yarn of choice is.   Knitting machine gauge will let you know how thick or thin the yarn can be to successfully knit on your knitting machine.

WARNING: It is important to note that some yarn stores will use a " McMorran Yarn Balance " to determine yarn weight.  While this is a good tool, it is only an estimate and open to error and human error.  Basically it is a rod that is balanced on a box and you place a strand of yarn on one end of the pole and cut the end off a little at a time until the rod is in balance.  You then measure the yarn on a ruler to assess weigh class.  As you can see, there is room for error here. This should not be the the only tool used in assessing a yarn's weight class.  If you are on a site that uses this tool, please disregard the information and look for other info about the yarn.  If the site also states WPI, which is wraps per inch, use that in assessing the weight class or ask for a sample of the yarn.  I have been on sites where they have stated a yarn is DK or even ARAN weight, and it was only a light SPORT weight.

                                          OK Here we go.....  


FIRST A FEW FACTS
Basically we look at how much yarn lengthwise is produced by spinning one (1) pound of raw fiber.

~One Pound of acrylic generally produces 500 yards
~One Pound of cotton or spun silk makes 840 yards
~Wool is 256 yards per pound and British Worsted Wool is 560 yards per pound
~Linen 300 yards per pound
                                                      

Yarn count is determined by how many times the yarn is spun and how many plies or strands are twisted together that are in the final product. Generally, the thinner the yarn the higher the number.  But there are two sets of numbers, USA and British.

BRITISH v. USA

In the USA 3/2 means size then plies.  In Great Britain 3/2 is plies then thickness

CAUTION with PLIES: Caution should be taken when looking at plies as all it actually/should mean is how many STRANDS are TWISTED together to make ONE strand, which is used in the final calculation.  For instance, 4ply cotton is a different thickness than 4 ply Linen.  PLY IS JUST HOW MANY STRANDS are in the yarn.  Each number has a different meaning but do not confuse ply with always being the same, it is different from yarn to yarn.  Below is a picture of plied yarn, see the twists in the yarn strand?  That means that there is 2 or more yarn strands twisted together.







To make things easier for you here is a list of "British" terms for yarn thickness stated in "PLY", and their equivalent.  They usually use the term "PLY" with a number before it and not terms like DK Weight or Baby Weight.  Also, each time you add a stand of yarn and twist them together to make 1 strand it increases the thickness.

Weight        British Ply           Other Term
 2/32             1 strand is 1 PLY       each strand added increase ply, 2 ply etc...
 2/30             1 strand is 2 PLY       each strand added increase ply, 3 ply etc...
 2/28             2 strand is 3 PLY       each strand added increase ply, 4 ply etc...
 2/24             2 strand is 3 PLY       each strand added increase ply
                     4 strand is  DK           Double Knit
 2/20             2 strand is 4 PLY
                     3 strand is DK
 2/16             Actual 2 PLY on its own, 1 strand
                     2 strands 4 PLY
                     3 strands DK
 2/14             1 strand 2 PLY
                     2 strands 4 PLY
 2/12             1 strand 3 PLY
                     2 strands DK
 2/10             4 PLY

EXAMPLES:
3/2 Linen = 3 is the number of plies twisted together to make one strand
                = 2 is the number of times the yarn has been spun, which is twice.

So Linen is 300 yards per pound spun twice = 600 yards AND then three stands are twisted together so the thickness is then learned by dividing the final spin, 600 yards, by the plies for thickness and/or, how many yarns are twisted together to create the final yarn, which is 3, so it is 200 yards per pound or really thick yarn.

BUT, as you can see, 2/20 varies greatly from yarn to yarn:

2/20’s COTTON = 8400 yard per pound
2/20 LINEN = 3000 yards per pound
2/20 WOOL = 2560 yards per pound




                               A WORD ABOUT COTTON
To make things even more confusing, you will need to change around the numbers for cotton.  Always use the standard of 840 yards per spin.  So, 3/2 cotton is 3 x 840 = 2520 yards per pound and then divide by the number 2 for plying 2 strands together to make 1 strand which changes the thickness to 1,260 yards per pound.

TIDBIT:My personal preference with cotton is gassed and/or mercerized, even though more expensive, the wear and tear on the processed cotton stands up better and looks new longer.  They are treatments that take out the stretch and fuzziness so that the cotton looks stand up to the test of time and has a little bit of sheen to it.  I love Egyptian cotton and in my opinion Egyptian mercerized and gassed the best against pilling, but also the most expensive.  But, if you are going through all the trouble in making something by hand, why not use the best products.

Below are conversions for the metric equivalent of US information that you will find on yarn depending where it is bought.  Most of the time, you will see metric information and balls will usually come in 50 or 100 grams.  Usually, yarn is sold by weight, NOT length so it is important to understand what you are buying in weight to figure out  how much you need for the project.

~1 oz = 28 grams

~1 pound = 454 grams about ½ a kilo

~1 kilo = 2.2 pounds

~100 grams = 3.5 oz

~50 grams = 1.75 oz


Finally, you need to remember that yarn from different manufacturers can also vary so it is important to know what kind of yarn you are buying and who from.  The example below shows how different wool types can vary.  Take note that the chart below uses "ply" to describe yarn thickness which I have cautioned you about, just stay away from ply as a term for yarn thickness and it will make things a lot easier.

COUNT   Yards/Pound      Other name
3/30                2600                Baby or 3-ply
2/20                2500                Baby or 3-ply
4/30               1920                 4-ply or fingering
2/15               1920                 4-ply or fingering
2/10               1280                 DK to Worsted
3/10                850                  Aran
3/8                  680                  Chunky


WOOL and the word "WORSTED"
“Worsted” Wool actually does not have anything to do with weight, it means that the yarn has been treated in such a way that all fibers are parallel. Worsted Wool is usually used in suits and fine garments as it is a soft and a really nice wool fiber.  I know this makes things more complicated but some manufacturers use this when defining and describing their yarn.  For all accounts remember it is a higher grade yarn than other wool yarns even though it is commonly used by people to describe a yarn weight rather than a yarn type.  I do not rely on this term and and look to other types of terms when looking at wool yarn in order to figuring out what weight it is.  Kind off the same thing as "ply".

BUT, when you do come upon this term it means that the wool is 560 yards per pound and is a British term, double worsted off course would be 1,120 yards per pound.  If this is incorrect please email me the correct definition but this is what I could find out.  I am confused by this term so I look to the actual yards per pound or meters per 100 grams to define the yarn thickness.

AN EXPLANATION of WPI, or Wraps per Inch




Wraps per inch, or WPI, is the number of strands that can lie next to each other on a ruler in an area of one (1) inch with no gaps.  That number dictates what yarn thickness you have.  It is a very easy way to figure out what weight yarn you have.  When wrapping the yarn around the ruler, make sure that you do not wrap tightly but also make sure there are no gaps and use a regular wooden ruler.  *** Now there is also COBWEB = 40 and "ZEPHYR" is even thinner.

FINGERING = 36-40
SOCK/BABY = 24-30
SPORT/BABY/LIGHT DK = 18-24
DK/DOUBLEKNIT/LIGHT WORSTED = 12-18
WORSTED/ARAN = 10-12
CHUNKY/HEAVY WORSTED = 8 >


DIFFERENT YARN WEIGHT SYSTEMS


What is Nm?
Nm is weight - it is Grams divided by yards x (times) 545.

EXAMPLE:
50 grams = 200 yards, this information, weight and length, is on the label:

                200 ÷ 50 = 4
                                   4 x 545 = 2180 yards per pound which is fingering weight,
BUT
If it is 3 ply, then you divide that number by three, 2180 ÷ 3 = x,  which is 726 yards per pound or heavy weight.

This number states how many meters or yards of yarn will come from 1 gram of weight

EXAMPLE:   a single ply of 1/28 yarn will give 28 meters per gram whilst 2/28s will give half that because it is twice as thick.

PLY has NOTHING to do with weight, just how many times the yarn is spun on itself, 8 ply could still be a light weight yarn.

Here is yet another way of looking at Nm that I found:
One nm equals 1,000 meters of yarn per kilogram (1,000 m/kg), no matter what (whether it’s wool or bamboo — it’s a constant). This equals 50 meters per 50 grams. A 1/8 nm yarn (usually just called “1/8,” without the nm) tells you that the yarn has been spun 8 times longer than the standard, and is therefore finer. You will get 8,000 meters per kilogram if your yarn is a “1/8.”  This standard means that a 1 Nm yarn will contain 1,000 meters per kilogram, or 50 meters per 50 grams.

The first number in the name, or the “1” in “1/8” indicates the number of plies in the yarn (remember what I said about plies?). A “1/8” yarn has one ply, a “2/8” yarn has 2 plies, etc.

Here’s where it gets tricky: a “2/8” yarn indicates the yarn was spun to 8,000 meters per kilogram, but then plied into a two-ply yarn. The finished yarn will therefore measure 4,000 meters per kilogram. A “3/8” yarn will have 2,666 meters/kilogram, or 8000 divided by 3.

How does the general numeric system compare to the CYCA chart? From thick to thin:
    4/8 yarn yields 1,120 yards per pound and is closest to what hand knitters consider a DK weight yarn.
    3/8 yarn yields 1,490 yards per pound, or “sport weight” yarn. Similar to a DK weight, but slightly thinner.
    2/8 yarn yields 2,240 yards per pound, for a fingering weight yarn.
    2/18 yarn yields 5,040 yards per pound, and is considered lace weight.
    2/20 yarn yields 5,600 yards per pound, and is also considered lace weight.
***2/24 yarn yields 5,960 yards per pound, and again, is considered lace weight but I cannot think of anything I would use this for unless I plied strands together to make a thicker yarn.

One thing to remember about "LACE-WEIGHT YARN" is that there are different variations now, from a feather weight lace yarn to a thicker light weight and then plain lace-weight.  Ask your dealer or store about how they categorize the lace-weight yarn as it can make a difference.  The  Yarn Craft Council of America  recently has actually changed their yarn weight definitions to accommodate the difference.  They now have a Zero Weight (0) and a 6 "Bulky - Roving" weight and 7 "Extra Extra Thick Yarn", Jumbo and Roving.

It is also good to remember that Lace Weight Yarns are usually hand knitted or crocheted on larger needles and with a knitting machine certain stitches may be knitted at a looser tension to create lacy, openwork patterns. Accordingly, a gauge range is difficult to determine. Always follow the gauge stated in your pattern.  I have included how many yards per pound for each weight (YPP - Yards Per Pound)

Lace: 36 - 40 Wraps per Inch 
0 - ZERO:
  Fingering/Feather Weight ~ 33 - 40 stitches/4" ~ 3,000-6,000 YPP

Super Fine: 24 - 30 Wraps per Inch 
1 - ONE:
  Sock/Fingering/Baby Weight ~ 27 - 32 stitches/4"
                  Sock: 3,000-6,000 YPP
                  Baby: 2,400-3,000 YPP
                  Fingering: 1,800-2,400 YPP.

Fine:  18 - 24 Wraps per Inch 
2 - TWO: Sport/Baby Weight ~ 23 - 26 stitches/4" ~ 1,300-1,800 YPP

Light:  12 - 18 Wraps per Inch
3 - THREE:  DK Weight/Light Worsted ~ 21 - 24 stitches/4" 

                      DK: 1,000-1,400 YPP
                     Light Worsted: 900-1,100 YPP

Medium:  10 - 12 Wraps per Inch 
4 - FOUR:
 Worsted/Aran Weight/Afghan ~ 16 - 20 stitches/4"
                   Worsted: 900-1,100 YPP
                   Aran: 700-1,000 YPP

Bulky or Thick:  8 or less Wraps per Inch
 5 - FIVE:
  Bulky Weight/Rug/Chuncky ~ 12 - 15 stitches/4" ~  500-700 YPP (Not for machine knitting, except intarsia or weaving)

Super Bulky or Extra Thick:
6 - SIX:
  Super Bulky Weight & Roving ~  7 - 11  stitches/4" ~ (Not for machine knitting except intarsia or weaving)

Jumbo or Extra, Extra Thick:
7 - SEVEN:  Jumbo & Roving ~  6> stitches/4" ~ Not for machine knitting

TIDBIT:  WOOL is 256 YPP
                 WORSTED can be 560 YPP
                 LINEN COUNT is 300 YPP
                 ENGLISH COTTON is 840 YPP


Next we will discuss DENIER and Tex.  Tex is more likely to be used in Canada and Europe, while Denier remains more common in the United States.

What is Denier? 
This system in used to number continuous filament yarns, EG: silk and man-made yarns such as rayon and fun fur. The length is a fixed number and the weight will vary on the type of yarn which is then measured in deniers.  Most synthetic yarns other than glass, raw and thrown silk yarns are sized by the metric and denier systems.  But reeled silk is sold by weight.

                          The denier count of a yarn = weight in grams per 9000 meters.
                                                                        The thicker the yarn, the higher the denier number becomes.

The metric yarn number is the weight in grams of a 450-meter length of the yarn divided by 0.05, or, another way of saying the same thing, what is the weight of a 9000-meter length of yarn.

SIDE NOTE ON SILK: Spun silk yarn, which is made from leftovers after filament silk has been produced, is numbered by different systems in the United States and the United Kingdom, one like that used for cotton. The smaller the number, the heavier the yarn.  Unlike cotton, the count in a fraction describes the finished yarn, not the plies.  Below is a picture of 100% silk yarn, it is just amazing when it comes to shine and vibrant color.

What is Tex?
Tex is a unit of measure for the lenght density of fibers and is defined as the mass in grams per 1000 meters. The unit code is "Tex". The most commonly used unit is actually the decitex, abbreviated dtex, which is the mass in grams per 10,000 meters. When measuring objects that consist of multiple fibers the term "filament tex" is sometimes used, referring to the weight in grams per 10,000 meters of a single filament.  
Tex is also used for measuring fiber size in many products, including cigarette filters, optical cable, yarn, and fabric.

The Tex system is also based on the fixed length system, ie: Weight per unit length. The Tex count represents the weight in grams per 1 kilometer (1000 meters) of yarn.  In other words the weight in grams per 1.000 meters of yarn, so 40Tex means that 1000 meters of yarn weighs 40 grams. The Tex number increases with the size of the yarn.

The yarns are labeled according to an international code. The yarn count number is followed by the word  "Tex". The term "folded" is used in preference to "plied" yarn when two or more yarns are twisted together, and the direction of the twist is included in the formation, which dictates the strength of the yarn and if it will have a tendency for the plies to unravel when worked with it.  Some yarn you want twisted in the same direction and other you change the direction with each strand.

EXAMPLE: R 20 Tex/ 2 S – two threads of 10 Tex are folded in an "S" direction, therefore the resultant count (R) will be 20 Tex because the weight is exactly doubled.

SUMMARY

"Yarn Count or the INDIRECT System" is usually used with traditional natural fibers and is based on the weight of the yarn per pound by how many hanks, balls etc…  Different fibers have different lengths.  THIS YARN COUNT SYSTEM IS MOST COMMON WITH YARNS.  If you want to get technical I have included yarn conversion charts in the down load section to help you convert this information numerically from one system to another. "Metric Count", Nm, is how many meters of yarn in 1 kilo and usually used for synthetic yarn but I also use it for any yarn.

                                  For all FIXED WEIGHT SYSTEMS, the LOWER the number the THICKER the yarn

                                       DIRECT count systems, Tex and Denier,the HIGHER the number the THICKER the yarn  

"Tex" is mostly used and is based on the weight in grams per 1000 meters of yarn.  "Denier" on the other hand is on weight of the yarn in grams per 9000 meters of yarn.  This is used in many industries including carpeting, upholstery, tire manufacture and not so much with yarn or textiles for garments but can be used with blended filament yarn and microfiber.   Just remember...

                                     
Fixed Weight, Indirect, Count = HIGHER the number THINNER the yarn

                                                 Fixed Length, Direct, Tex = HIGHER the number THICKER the yarn