Fabric Weight and Conversions
Posted by Guest Author on Mar 17, 2008 at 10:54 am / Textiles and Inputs, Tutorial / Trackback
Today we have a guest entry from Jennifer Ennis. Jennifer is a DE from Winnipeg Canada. She has worked in the garment industry for both an importer and domestic producer. Her educational background is diverse mix of textile science, design and economics (sustainable development) which includes, in her opinion, far too much time in front of a HunterLab colorimeter. Thanks Jenn!
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Let’s talk about fabric weight. If you’ve been confused with converting weights of fabrics, most often described as “grams per square meter” or “ounces per square yard”, this should help you. Technically, both of these refer to “fabric mass”. I make this distinction only because if you try and look up test methods to determine weight (fabric mass) you’ll not find it. But okay, I am calling it “weight”.
Previously when I worked for a garment manufacturer, I was often working on fabric testing mostly because I paid attention in textile science class. It came in handy to save few rear ends during my time there so it is useful stuff to know (I‘d also like mention that I paid attention in design and economics too).
I tested fabrics from Asia, the United States and Europe (Italy specifically) and I have run across many ways weight was described. I would hesitate to suggest that fabrics were deliberately mislabeled to mislead people but based on what I’ve seen, I can’t say they weren’t either. For example, one mill told us the fabric was 14 oz and everyone assume it was per square yard when in fact it was per liner yard and ended up only weighing 12 oz/yd2. So it is important to understand what unit is being measured and always, if in doubt, clarify and verify.
In my experience, the two most common descriptions of weight were:
- GSM aka g/m2 = grams per square meter
- oz/yd2 = ounces per yard squared
I have also run across
- g/m or gram per linear meter
- oz/yd or ounces per linear yard,
- g/yd2 or gram per yard squared *
- oz/m2 or oz per meter squared *
* why in heaven’s name you would mix the two systems (imperial and metric) is beyond me but people do.
Gsm is the standard and I am not just saying this because I one of those weird people trained in new math and metric. Here are three reasons:
- Metric is ISO standard units and used in ASTM D3776-07 Standard Test Methods for Mass Per Unit Area of fabric (that is the test method you be asking a material testing lab to run)
- Equipment is inexpensive and commonly available for use in measuring these units, even in office situations.
- It is internationally understood (USA is one of the only countries not using metric system)
Conversion formulas:
There is an easy way to convert gsm to oz/yd2.
Divide the gsm by 33.906 – really that is all.
To determine gsm from oz/yd2 you do the reverse – multiple by 33.906.
If it helps, this is what the formulas are based upon:
- 1 oz = 28.3495231 grams
- 1 yard = 0.9144 meters
- 1 yard squared = (.9144 m x .9144 m) =.83612736 meters squared
Therefore
- 1 oz/yd2 = 28.3495231g/.83612736 m2 = 33.90574744 g/m2
- Rounded up to three decimal places it is 33.906
If you don’t like doing the math –I dislike doing calculations repeatedly– you may prefer to use tables to look things up. I know I do. To make it easier for you, I’ve attached a table I made (pdf 16kb) that shows conversion for the most common weights of 50 gsm to 689 gsm to oz/yd2. I recommend sticking it in a plastic protector sheet, storing it in a binder or attached to a cork board and you are all set.
If there is sufficient interest or questions, I can write another part to cover other conversions and perhaps another section on how to do internal approval testing and limitations. I’m thinking a good post would be about converting GSM to oz/linear yard in order to calculate for dye houses i.e. how many yards to make up x number pounds of fabric.
35 Responses to “Fabric Weight and Conversions”
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March 17th, 2008
12:30 PM
Yes, please! I’d love to see both of the additional posts you mentioned. This is all very helpful. I never thought to verify fabric weight! Eeep.
March 18th, 2008
6:30 PM
Very interesting, and timely for me. I’ve been diving into fabric weights for the purposes of more precise dying (on a craft level, not manufacturing). The linear yard vs. square yard is an interesting flub – wouldn’t have thought of it. Any other posts would be read with delight.
So when you calculated the 14 oz. fabric was actually 12 oz. you just cut out a square yard and weighed it? Is it that basic?
March 19th, 2008
8:41 AM
Erin
Actually you cut out a small circle using a die and weight it in gsm and converted it to oz/yd. I then deduced that based on the standard width of that type of fabric (which I new from experience) that they must have been quoting the weight in oz per linear yard. I will talk more about that conversion and the equipment requirements in my other posts.
April 2nd, 2008
12:07 PM
How do I convert oz/linear yard to oz/yard squared? For emample
1.2 oz/yard square = ? oz/linear yard
April 2nd, 2008
12:36 PM
Width of 1 yd (66″) X length of 1 yd (36″) = 1.667 yd2.
Then, you multiply:
oz/lin yd X 1.667 yd2 = oz/yd2
The lin yd weight is helpful for dyeing, shipping, or calculating shelf space. But, garment info is based on yarn density (i.e. oz/yd2).
April 18th, 2008
1:29 PM
How do you convert grams per l/m to gram per m2?
For example 270 gr/ml = 186 gr/m2 but I do not know the calucalation and I assume it depends on the width of the goods?
April 18th, 2008
2:56 PM
In answer to Bobby and KW, yes, you need to know the width of goods to convert between linear yards (which measures length) and square yards (which measures area). Area is length times width.
Suppose your goods are 54 inches wide. That’s one and a half yards wide. So every linear yard of goods 54″ wide covers an area of 1.5 square yards. If you had goods 72 inches wide (two yards), every linear yard of goods 72″ wide covers an area of 2 square yards.
[Aside: Be glad we are not in the lumber business and talking about board feet.]
Since mills seldom weave to a nice multiple of meter or yard widths, you are going to have to break out the calculator or scratch paper and do some arithmetic to convert between linear yards and square yards. J C gave an example just a couple of comments above.
Suppose you have a fabric weight given in ounces per square yard (grams per square meter), and you want to know the weight per linear yard (linear meter). Find the fabric width in yards (meters) and multiply the given weight times that number.
Suppose you have a fabric weight given in ounces per linear yard (grams per linear meter), and you want to know the weight per square yard (square meter). Find the fabric width in yards (meters) and divide the given weight by that number.
June 24th, 2008
1:20 PM
Your articles are VERY helpful. We have learned many of these things the hard way, but have somehow managed to get our clothing company off the ground in spite of it all. Can you please direct us to a company or source that sells the punch die and scales for testing fabric density?
Thank You
June 30th, 2008
8:47 AM
This is an extremely useful post, especially for a European newly arrived in US and starting a children’s clothing line. I have mostly worked with Gsm standards and found it quite complicated and time-consuming to change into a new system.
Could you by the way explain what “per liner yard” means?
Thank you so much for sharing your knowledge with everybody. I am not used to this wonderful attitude.
June 30th, 2008
5:12 PM
Bente, a “linear yard” just means one yard long (36 inches), no matter how wide the fabric is. The use of the word “linear” helps to avoid confusion with “square yard”. Some fabric weights are given per area, while others are given per length. In the case of length, you must also know the width of the fabric to determine the useful weight of the fabric. See my comment from 18 April, just above.
Let me try this another way: What we really want to know is the weight per area of the fabric. If the mill provides the measurement in grams per square meter or ounces per square yard, that is what we want to know, so we don’t have to do anything more. But often, mills give us a measurement in grams per linear meter or ounces per linear yard. To get what we really want to know, we have to have the width of the fabric, too. Given the width and a weight per length, we can compute the weight per area.
July 15th, 2008
7:50 AM
I have a formula as below:
Fabric = 210g/meter square
Fabric width = 80 inches
Yard need per garment = 1.03 yard/pc
The coversion as follow:
1 lb fabric will have 1/0.00082/210/80*16 yd of fabric i.e. equal to 1.16144 yard. Therefore 1KG of fabric with 1.16144*2.204 yd i.e equal to 2.5598 yd of fabric.
Hence the consumption of one pc of garment will be 1.03/2.5598 kg. i.e. equal to 0.4023 kg
How to explain this formula??
1 lb fabric = 1/0.00082/210/80*16 yd
July 15th, 2008
7:26 PM
Wing Wing asks “How to explain this formula?? 1 lb fabric = 1/0.00082/210/80*16 yd”
As a practicing engineer, this kind of formula infuriates me. It is sloppy, cryptic, and mixes units of measurement. I was able to recompute the answer in two different ways much faster than I could come up with an explanation for the formula. Fortunately, nothing more advanced than high school math is needed.
First, let me show how I would compute it.
1 pound (lb) is about 454 grams.
454 grams at 210 g/m^2 is about 2.162 m^2.
1 m is about 1.094 yd
1 m^2 is about 1.196 yd^2
2.162 m^2 is about 2.586 yd^2.
80 in is about 2.222 yd.
2.586 yd^2 at 2.222 yd width is about 1.164 linear yd.
So, the overall formula I would use is
1 lb fabric = ((454/210)*1.196)/2.222 yd = 1.164 yd
You can also use the conversion given in the article at the top of this thread:
1 oz/yd^2 = 33.906 g/m^2
210 g/m^2 is about 6.194 oz/yd^2
1 lb = 16 oz
6.194 oz/yd^2 is 0.3871 lb/yd^2
1 lb at 0.3781 lb/yd^2 = 2.583 yd^2
The overall formula would be
1 lb = (1/((210/33.906)/16)/2.222 yd = 1.163 yd
The answer comes out a bit different due to arithmetic rounding.
Notice that both of my answers are closer to each other than to the 1.1614 of the question.
OK, now let’s look at the formula
1 lb = 1/0.00082/210/80*16 yd
The 210 is obviously the fabric weight in g/m^2. The 80 is the fabric width in inches. The 16 is presumably the number of ounces in a pound. The mystery is the 0.00082.
The order in which those divisions should be done is unclear, so we will try to figure that out, too. We know the answer is supposed to be 1.1614. As it turns out, just doing the operations from left to right gives that answer, so we could rewrite the formula more explicitly as
1 lb = (((1/0.00082)/210)/80)*16 yd
Since we have pounds on the left and yards on the right, the overall expression has to have the dimensions of yd/lb. We have
* 16 oz/lb [This is a fixed conversion constant.]
/ 210 g/m^2 [This is the weight of the fabric.]
/ 80 in [This is the width of the fabric.]
or 0.0009524 (oz*m^2)/(lb*g*in)
so what’s left has to have the dimensions of (yd*in*g)/(m^2*oz) to cancel out everything except yd/lb. For reasons I am not going to stop and explain, we can’t compute anything with that. Instead, we will look for an expression with equivalent dimensions of (yd^2*in*g)/(m^2*yd*oz).
There are 1.196 yd^2/m^2. [This is a fixed conversion constant.]
There are 36 in/yd. [This is a fixed conversion constant.]
There are 28.35 g/oz. [This is a fixed conversion constant.]
Multiply all those together to get 1220.6, which is 1/0.0008192, our mystery number.
So the original formula
1 lb = (((1/0.00082)/210)/80)*16 yd
can be rewritten as
1 lb = (16 * 28.35 * 1.196 * 36) / (210 * 80) yd
To break that down into simpler steps:
1 lb = (16 oz/lb * 28.35 g/oz) = 453.6 g
453.6 g / 210 g/m^2 * 1.196 yd^2/m^2 = 2.583 yd^2
2.583 yd^2 / (80 in / 36 in/yd) = 1.163 yd
And in fact, if you use the more accurate value of 0.0008192 instead of 0.00082, you get the answer of 1.163 yards. And if the author of that formula was going to fold three of the conversion constants into one mystery number, I don’t understand why he left the fourth one (16) out. The formula could have been written as (the equally mysterious, but simpler)
1 lb = 19530 / (210 * 80) yd
Wing Wing, that is the explanation of that very bad formula. However, you did not need that formula. The information you had available was sufficient to compute the same answer, more clearly and also more accurately.
August 12th, 2008
2:49 PM
So where can you buy the machine with the die to do the testing.
August 16th, 2008
3:13 PM
hi!
one difficulty i face while costing knitted garments is to know yarn counts when gsm is given.is there a ready recokner or a table u have that u can share which can help to resolve this problem i face.
August 20th, 2008
3:26 PM
Andrea, the objective of the die is to cut the same size of fabric for weighing each time, very quickly and without human error. However, you can cut a sample for weighing by hand if you measure and cut carefully. Since Jennifer didn’t say, I am going to guess that the die would be used with a “clicker” hydraulic press, often used for cutting leather or plastic with sharp metal dies.
Raghav, I don’t know of any fixed conversion between yarn counts and fabric weight. While yarn count gives the yarn spacing and size, yarns can be spun tightly or loosely for a given yarn size and this will have a direct impact on the fabric weight. The specific gravity of the yarn material (polyester, acrylic, cotton, etc) will also affect fabric weight for a given yarn count. Knits would vary even more than woven fabrics because they can be knitted “thickly” or “thinly” with the same yarn count, so the knit construction (as well as the yarn count) is important.
September 2nd, 2008
5:50 AM
If a fabric’s construction is
cotton 80/2 x cotton 80/2,120 X 100,and width is 56 inches,
how to caculate the weight in gsm ?
December 31st, 2008
2:41 AM
Hi
can somebody give the answer to sfriedberg ? As I find it is very interesting too.
April 18th, 2009
12:09 AM
forward the GSM calculation formula if we know the count, coarse/inch, vales/inch and knitting dia.
April 22nd, 2009
10:26 PM
Can someone pls reply to raghav chhabra’s question……………I am too facing the same situation while doing knit costing !!
April 23rd, 2009
11:37 AM
I responded to Raghav Chabrav’s question back in August of last year. There is no simple or predictable relationship between fabric weight (gsm) and yarn counts, generally speaking. To produce any kind of table or equation, you must ALSO know many other values, such as yarn density or size, the weave and thickness of the fabric, etc. It is easier to count threads with a microscope to get your yarn count directly than to compute it!
For a given type of fabric (say, 100% cotton broadcloth), one could prepare a table of yarn counts to fabric weights. But this table would not be correct for a different type of fabric. And I do not have access to any such tables. If you are doing costing, you probably need the data for the specific mill or machinery that will be producing your fabric.
I suggest that you make your own table from fabric data that you trust. All you need is three or four examples where you have both the fabric weight and the yarn counts. Then you can interpolate between known data points to get new values. Or, you can pay professional fees to a textile scientist (I am not one) to have him prepare a table for you.
May 14th, 2009
4:00 PM
hi, i am wondering if you can give any information on weighing sweater yarns. for example, in the industry a finished sweater garment is measured in lbs/doz., so they are weighing the total yarn used to make a complete garment. knowing the yarn size and number of ends in advance will help you to guess what the final weight might be, but the tension, stitch and construction affect the finished weight just as much. the finished weight will vary much more than a standard knit or woven fabric that is being cut instead of constructed to shape.
that being said, if you have a sweater that is 10.5 lbs/doz, does that just mean that if you had a dozen of that sweater, the average weight would be 10.5 lbs?
May 28th, 2009
1:08 AM
Thanks for this page it will come in handy when selling fabric on my website. Thickness/weight is such a hard thing to describe on a website. What is medium , light etc. The only problem i can see is that these figures will mean little to the customer. most wont understand 120g/m. that could mean thick, thin etc.
what is needed is a fabric scale that people understand straight away and compare with. (please note these are figures not actuall just pulled from the air)
50g toilet paper
100g thin poly cotton/shirt material
200g thick poly cotton fabric
300g deck chair canvass
400g kids craft grade felt
Has anyone got any real life values for real items ?
I will bookmark this site and add some of mine over the next couple of weeks
July 19th, 2009
6:08 PM
Hi, my question relates to fabric which is described, for example, as 60/40 Cotton/Polyester. Are these percentages by weight or what? If not, how can I determine the % by weight of a fabric’s composition?
August 18th, 2009
10:47 PM
Arthur, the US rules require percentage by weight. From the way you phrased your question, that’s what you wanted, so no work to be done.
If you are given something labeled with percentage by volume or by yarn count, you have only three practical choices. 1) Ask the mill that made the fabric what the percentage by weight is. 2) Assume the percentage by volume is close enough to the percentage by weight to use the same numbers. 3) Hire a laboratory or textile scientist to actually measure the proportions by weight in the fabric.
As I mentioned a couple of times above, (with the exception of monofilaments) there are no reliable numbers of yard or thread density, so you can’t go from volume to weight with any accuracy. (There are lots and lots of approximate, ballpark figures, but they may be 10% or even more off of the actual values for your fabric.) However, most yarn materials have very roughly similar densities, so you might be able to get by with choice #2. If that’s not accurate enough, or the penalties for an inaccurate label are large enough, you’re going to have to hire an expert to get your numbers.
September 20th, 2009
7:42 AM
Is denier also a measure of fabric weight?
and how about “T”
thanks
September 21st, 2009
3:25 PM
Irene, “denier” is technically a measure of monofilament yarn size rather than fabric weight. There is a reasonably good relationship between fabric weight and denier for a given weave, enough that people have no difficulty recognizing 200D fabric as a packcloth and 1000D as luggage material. But different weaves (or mill processing) can produce different fabric weights from the same size denier yarns. Also, the water repellant or waterproof coatings often applied to nylon fabrics described by “denier” will add directly to the fabric weight.
“T” is short for Tex, and there is rather detailed article that includes Tex, denier and lots of other thread sizing systems here
October 20th, 2009
3:45 PM
Please advise meaning of 50D/72F re a polyester fabric. Could it mean denier 50; filaments 72?
please advise how to convert fabric weight 60 grams/sq. meter to denier, if possible.
November 11th, 2009
7:52 PM
jERRY, I believe you are correct, and that notation seems to be used mostly with textured yarns (e.g., “wooly”). I was not familiar with this notation, but some quick web research found a table with the heading “Denier / Filaments”. Presumably, a 50D/36F yarn is made of fewer, heavier filaments than a 50D/72F yarn.
I don’t have a reliable way of going from fabric weight to denier for reasons discussed immediately above. However, looking at some sample swatches I have, an uncoated 60gsm fabric is probably close to a 60 denier. If it’s coated, it’s probably closer to a 40 or 50 denier.
For everyone, I need to correct a consistent misstatement of mine. The denier thread sizing system is used for filament yarns, not just monofilament. Monofilament is like fishing line, one solid cylinder. Filament yarns are not limited to monofilaments, and include silk, polyester and nylon yarns of many fine filaments. My apologies.
December 6th, 2009
7:02 AM
I need a solution on the following:
Available information : Fabric Required is Reed 66 & Pick 44 / Warp 10s PC (65% Cotton & 35 % Polyester) & Weft 14s OE. Bleached White (Peroxide). The Warping Charges @ INR. 12 per Kg & Weaving Charges @ INR 0.28 Per Pick. Finished Fabric Width 94″ after process.
Required Information : How to calculate Cost of fabric (Grey) per Meter @ Yarn Rate INR 90 for 10s PC & INR 80 Per Kg for 14s OE? What Should be the width of grey fabric before bleaching?
December 6th, 2009
8:45 AM
@Selvadurai
With a question with that much technical detail, I am guessing that there may be some money riding on getting the answer correct. Do you really want an answer that you can get for free? I would say no. You should pay for the answer to this question. I would suggest starting with the company that is going to be producing the fabric.
December 6th, 2009
9:50 PM
Dear Sir,
I want fabric construction calculating method. Because, buyer given only “GSM” .
In that how much reed and pick, & cotton count insert on the loom.
please tell me sir.
December 7th, 2009
12:47 PM
Ganesh (and Selvadurai) do you have a textile engineering reference book? It may be a worthwhile investment. I mean, I’m delighted if someone in the crowd knows the answers to these questions but even from my limited knowledge of the topic, know that the variables and the costs of each (subject to market conditions), are considerable.
December 7th, 2009
9:26 PM
I want to knows the relation between GSM & Yarn.
There is lot of fabric like S/J, Laycra Jersey, 1 X 1, 2 X 2,
Yarn Count 24’s-30’s
How Can I make 24′ S/j- which gsm will came like also othere fabric
January 27th, 2010
10:51 PM
For Knitted Fabrics
gsm 210 g/meter square
width 80 inches
consumton 1.03 yard/pc
1 lb fabric will have 1.161440186 yd of Fabric
1.270166432 Mtr of Fabric
1KG of fabric 2.55981417 yd of Fabric
1KG of fabric 2.340694077 Mtr of Fabric
1 mtr of fabic will have 0.005625408 Kg
1 Yd of fabric will have 0.390653358 Kg
January 27th, 2010
10:52 PM
gsm 210 g/meter square
width 80 inches
1 lb fabric will have 1.161440186 yd of Fabric
1 lb fabric will have 1.270166432 Mtr of Fabric
1KG of fabric 2.55981417 yd of Fabric
1KG of fabric 2.340694077 Mtr of Fabric
1 mtr of fabic will have 0.005625408 Kg
1 Yd of fabric will have 0.390653358 Kg