| Sewing Patterns for the Modern Woman - Blog Post: Demystifying Fabric Weight

Demystifying Fabric Weight

By Allie

Allie is the co-founder of Indiesew and creator of all things pretty on the site. Follow Allie and receive other Indiesew updates by subscribing to the blog. | Demystifying Fabric Weight 

It wasn’t until we opened the Indiesew Fabric Shop, that I started to understand the intricacies of textiles. I knew of a few broad categories of fabric (chambrays, lawns, and those I referred to as simply rayons), but I didn’t understand how all of the different characteristics of fabric work together to create a wearable textile. Perhaps the most mysterious of those characteristics was fabric weight. 

Today I thought it would be useful to offer a primer on fabric weight. You may not consider fabric weight useful in your sewing hobby right now, but eventually you’ll come face to face with ordering fabric online and lacking one very vital piece of information, the per square yard/meter weight. Fabric weight is just one piece of the entire makeup of a fabric, but an incredibly useful one.

Indiesew | Silk Fabric


fabric weight defined

Fabric weight is generally listed in the US as ounces per square yard and in the UK as grams per square meter (GSM). Sometimes in the US, you'll see fabric weights listed as just ounces (for example, a 10-ounce French terry shown below). It can be assumed that this is the weight of the fabric per square yard.

Indiesew Grey French Terry

This is the standardized way of listing fabric weights because fabric can come in a wide range of widths from the manufacturer. Thus, fabric is weighed on a scale as a 36” by 36” square, or a formula is used to find that value based on a different size of fabric. More on that below! 

Indiesew | Chambray Fabric

The per square yard/meter weight of the fabric only tells us how much the fabric weighs. It doesn’t indicate how loose or dense the weave or knit is. And it varies widely depending on the type of fiber that is used to create the fabric.


Why is fabric weight important?

In many sewing patterns, designers will list a suitable fabric weight for the garment. This information is important to note. For example, sewing the Lander Pant in a 4-ounce linen as opposed to a 10-ounce canvas will give the pants a very different appearance.

Generally, the less a fabric weighs, the more pliable and drapey it will be, and the more it will breathe in hot weather. Also, the lighter a fabric is, the more sheer or see-through it may appear. For reference, fabrics that weigh less than 2-ounces per square yard will generally be somewhat sheer. Once in the 4-ounce range and above, a fabric tends to be less see-through.

The heavier a fabric is, the more durable it will be to wear and washing. This is particularly true of twill weave fabrics like denim. Heavier fabrics are generally more opaque, rarely needing a lining for skirts and dresses.

But these are not hard and fast rules. Many lawns and chambray can be very lightweight, but have a stiffer appearance due to the fiber content. Our rayon and Tencel twills often have a beautiful heavy drape, but weigh anywhere from 6 to 8 ounces per yard.

It’s important to consider the entire list of characteristics when choosing a fabric, something that you will naturally start to do as you sew more. You’ll eventually learn that cotton twills are stiffer than rayon or Tencel twill. You’ll learn that cotton voile and rayon voile have a completely different hand.  


Fabric Weight Quick Reference

But as a general reference, here’s a quick guide of fabric weights for the most commonly found fabrics:

weightcommon substrates
2 to 3 oz. per square yard (roughly 57 to 85 GSM) voile, crepe (especially 100% silk or poly crepes), chiffon, lightweight cotton shirtings, lightweight chambray
4 to 5 oz. per square yard (roughly 113 to 142 GSM) rayon crepe, rayon challis, cotton-based knits, cotton shirtings, chambray, linen, double gauze and double cloth, charmeuse
6 to 8 oz. per square yard (roughly 170 to 227 GSM) Tencel and rayon twills, French terry, rayon-based knits, modal and bamboo knits, ribbed knits, linen
9 to 12 oz. per square yard (roughly 255 to 340 GSM) denim, ponte knits, cotton twill, corduroy, waterproof fabrics, jacquard, wool melton, most coatings
12+ oz. per square yard (340+ GSM) canvas, duck, upholstery


How can I calculate fabric weight at home?

The fabric we sell is overstock apparel yardage from the LA Fashion District and has no information attached to it from the supplier. For every bolt, we determine the fabric type and weight. And today we’re letting you in on our fabric weight formula!

Instead of cutting a square yard of fabric (and thus, wasting it) to simply to find the fabric weight, we cut off a 1/4-yard piece that we’ll use to photograph the fabric. We use this scale (it's incredibly accurate) to weigh the 1/4-yard cut of fabric. If you have a kitchen scale you can use that too!

Then, we use this spreadsheet, to input the fabric width (in inches) and 1/4-yard weight (in ounces). The formula tells us the square yard weight and the full yard weight. That spreadsheet also has calculations for grams per square meter for those folks on the metric system.

But for your use at home, you don’t need to cut off a 1/4-yard chunk of fabric. The formula lets you enter the length in inches so that you can weigh your entire cut of fabric to find out the square yard weight.

Once you find out how much your fabric weighs, you'll get a better sense of what type of garment it will work best for. Here's a very general guideline for garment types and fabric weight recommendations. But take this with a grain of salt, as some garments will look great in many different fabric types:

garment typerecommended fabric weight (per Square yard)
Flowy summer blouses, skirts and dresses (generally with a lining) 2 to 4 ounces (57 to 113 GSM)
Structured midweight tops, dresses, and skirts 4 to 7 ounces (113 to 198 GSM)
Fall jackets, trousers, structured skirts, stretch jeans 8 to 12 ounces (227 to 340 GSM)
Non-stretch jeans, jackets, very structured pants or skirts 10 to 13 ounces (284 to 367 GSM)
Winter coats 12+ ounces (340+ GSM)

We don’t generally offer swatches at Indiesew, because many of our fabrics sell before you’d receive the swatch and be able to buy the fabric. Because of that reason, we try to give the best possible description of the fabric, and a huge part of that is listing fabric weight. 

I hope this helps demystify fabric weights! We want you to feel comfortable know how fabric weights affect drape, opacity, and durability, but also encourage you to consider other factors like fiber content and weave type. Our Fabric Files series contains super detailed blog posts on a specific type of fabric. Be sure to give those a read for a particular substrate.

Happy sewing!

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