Fabric Weight Category Chart (GSM & Oz)

Posted by Jennifer Dobbin on

Here’s a useful little breakdown of fabric weights and links to some fabrics and some pattern favorites: 

 

Fabric Weight Category Chart (GSM & Oz)

Category

GSM (Grams)

Oz/yd2 (Ounces)

Typical Uses

 

Ultra Light

<100 gsm

< 3 oz

Sheer curtains, lining, voile

Rayon, Poplin

Rumi Dress and Top

 

Lightweight

100–170 gsm

3–5 oz

Blouses, shirts, summer dresses

Rayon, Poplin, Knits, Muslin/Double Cloth

Bardon Dress

 

Midweight

170–340 gsm

5-10 oz

Tees, light pants, quilting

Knits, Quilting Cotton, Linen, Canvas, Twill

Beachcomber Jacket,

Grow with me Pajamas

 

Heavyweight

340–400 gsm

10-12 oz

Denim, jackets, canvas

Denim

Falconer Pants

 

Ultra Heavy

>400 gsm

> 12 oz

Upholstery, heavy workwear

 

 

Key Fabric Weight Facts

  • GSM Definition: Grams per Square Meter—metric standard.
  • Oz/yd² Definition: Ounces per Square Yard—imperial standard.
  • Conversion Formula: Multiply GSM by 0.0295 to get oz/yd².
  • Context: Higher GSM/Oz means denser, thicker fabric, but not necessarily better quality.
  • Denim Note: Denim is often cited in oz (e.g., 10oz is approx. 340 GSM). 

Share this post