GSM Weight Guide: Choosing the Right Fabric Weight
GSM (g/m²) is a fabric’s weight per square metre and the fastest indicator of what it is for: tees typically sit at ~120–180 g/m², sweatshirts and joggers at ~250–350 g/m², jacket linings and structured outerwear at ~300 g/m² and above. With the same structure and yarn, higher GSM means more opacity and generally more durability.
5 sections 5 terms ~2 min
GSM (grams per square metre) is the weight of one square metre of fabric and the basic measure of how light or heavy it is. At the same structure and yarn, a higher GSM means a thicker, more opaque and usually more durable fabric. But GSM alone does not equal quality; yarn count (denier), knit structure and density also shape the hand together.
What weight affects
- Hand: low GSM feels light/fluid, high GSM full/structured.
- Opacity: low GSM can be see-through; in light colours and white, underlayers may show.
- Durability: heavier fabric is generally more resistant to abrasion and laundering.
- Warmth: high GSM is more insulating/warm; low GSM is cooler and more breathable.
- Cost and cutting yield: high GSM means more yarn and higher cost.
Tee (~120–180 g/m²)
Lightweight performance and everyday tees usually sit in this range. The low end (120–150) is very light, cool and fluid but carries see-through and durability risk due to thinness. The upper end (160–180) gives a fuller-bodied, more opaque, longer-lasting, premium tee hand.
Sweatshirt / joggers (~250–350 g/m²)
Sweatshirts and hoodies use heavier structures, usually brushed-back fabric (fleece) or thick interlock. This range delivers warmth, a full drape and durability. Very high weights feel more premium but make a heavier product that dries more slowly.
Outerwear / structured pieces (~300 g/m² and up)
Jacket linings, scuba, heavy fleece and technical outer layers run at higher weights. Here the priority is insulation, shape retention and durability; the hand is built on structure and body rather than softness.
Tips for choosing GSM
First fix the product’s end use and the hand you want, then pick the GSM range. Because the same GSM in a different yarn and structure can give very different fabrics, always confirm a target weight against a real sample, judging actual hand and opacity.
Frequently asked questions
What GSM should a T-shirt be?
Light performance and everyday tees typically sit in the ~120–180 g/m² band. The low end (120–150) is very light, cool and fluid, but its thinness brings transparency and durability risk. The high end (160–180) gives a fuller-bodied, more opaque and longer-lasting premium tee hand. Sweatshirts and joggers run ~250–350, while jacket linings and structured outerwear sit at ~300 g/m² and above.
Does a higher GSM mean better fabric?
No. At the same structure and yarn, a higher GSM means a thicker, more opaque and generally more durable fabric — but GSM alone does not indicate quality: yarn count, knit structure and density set the hand together. Because the same GSM can yield very different fabrics with different yarns and structures, always confirm the target weight with a sample, judging real hand and opacity.