GSM Explained: Choosing Fabric Weight for Hoodies, Tees and Activewear

GSM stands for grams per square metre. It tells you how much a fabric weighs, and by extension roughly how substantial it feels. It does not tell you how good the fabric is — a poorly spun 300 GSM cotton will feel worse than a well-made 200 GSM one — but it is the fastest shorthand for setting expectations.

T-shirts

140–160 GSM — Lightweight. Common in promotional and event tees. Drapes close to the body and will show what is underneath in lighter colours.

180–200 GSM — The standard retail weight. Holds shape reasonably, prints well, costs sensibly.

220–260 GSM — Heavyweight. This is where a tee starts to stand away from the body and read as a considered product. Most streetwear brands specifying "heavyweight" are in this band.

280 GSM and above — Very heavy. Impressive on the rail, but check it against your climate. In warm markets this sells poorly no matter how good it looks.

Hoodies and sweatshirts

280–320 GSM — Lightweight fleece. Suits layering pieces and warmer climates.

350–400 GSM — The mainstream sweet spot. Substantial without being stiff, and the most forgiving weight for print and embroidery.

420–500 GSM — Heavyweight. Dense brushed back, structured hood, and the weight most premium streetwear brands are chasing. Expect higher fabric cost and a longer production time; heavier fabric is slower to cut and sew.

Above 500 GSM — Specialist. Achievable, but the garment becomes rigid and shipping costs climb noticeably.

Activewear

Weight matters less here than composition and construction, but as a rough guide:

130–180 GSM — Performance tees, running singlets, lightweight shorts.

190–240 GSM — Mid-weight leggings, training tops, seamless pieces.

250–300 GSM — Sculpting leggings, compression pieces, cooler-weather layers.

For leggings, do not select on GSM alone. A 260 GSM fabric with poor elastane recovery will bag at the knee within a month. Ask for a recovery test result, and for opacity testing under stretch.

Where to spend

If your budget is fixed, put weight into the pieces where customers physically judge quality: outerwear and hoodies. A heavyweight hoodie communicates value instantly. On a t-shirt, moving from 180 to 240 GSM is noticeable; moving from 240 to 280 GSM mostly adds cost.