Fabrics
What Does GSM Mean? Fabric Weight for Sportswear, Explained
GSM is the weight of a fabric in grams per square metre. Here is what the number tells you, what it doesn't, and what GSM is best for jerseys, hoodies, T-shirts and leggings.
GSM stands for grams per square metre. It is the weight of one square metre of fabric. A 140 GSM jersey fabric weighs 140 grams per square metre; a 350 GSM hoodie fleece weighs 350 grams.
It is the most common number on any sportswear spec sheet, and one of the most misunderstood.
What GSM tells you
Within the same type of fabric, a higher GSM usually means:
- thicker and more opaque — less likely to show through in white or light colours;
- warmer — more material traps more air;
- more durable — more yarn to wear through;
- slower to dry and less breathable;
- more expensive — you are buying more fibre per garment, and it costs more to ship.
What GSM doesn't tell you
GSM only compares like with like. A 140 GSM mesh and a 140 GSM interlock feel completely different, because the knit structure matters as much as the weight. A 180 GSM stretch fabric with elastane will feel heavier and more substantial than a 180 GSM cotton jersey.
GSM also says nothing about quality. A heavy fabric knitted from poor yarn will pill and fade faster than a lighter fabric made well.
What GSM is best for sportswear?
These are common ranges. Treat them as starting points to discuss, not fixed rules.
| Product | Common range | Notes |
|---|---|---|
| Football / volleyball shirts | 120–160 GSM | Lighter for hot climates, heavier for a premium feel |
| Basketball vests | 120–140 GSM | Usually mesh |
| Rugby jerseys | 200–260 GSM | Heavier to resist grabbing |
| Performance tees | 130–180 GSM | Stretch fabrics sit at the higher end |
| Cotton T-shirts | 160–260 GSM | 220+ for "heavyweight" brand tees |
| Polos | 160–220 GSM | Pique |
| Leggings & compression | 200–260 GSM | Opacity matters — test in a squat |
| Tracksuits | 200–260 GSM | Tricot |
| Hoodies | 280–420 GSM | 300–320 for clubs, 380+ for lifestyle brands |
Heavier is not automatically better
Brands sometimes push GSM up because a heavier garment feels more "premium" in the hand. That can be right for a lifestyle hoodie. For a match shirt worn in summer, it is the wrong choice: the shirt will be hotter, heavier when wet and more expensive to ship, with no benefit on the pitch.
Ask what the garment needs to do. A sprinter, a rugby forward and a supporter on a cold terrace need very different fabrics.
GSM and price
Because fabric is usually the largest single cost in a garment, GSM has a direct effect on price. Moving a hoodie from 320 to 400 GSM adds fabric cost and shipping weight on every piece. If you are working to a target price, ask your manufacturer what the same garment costs at two or three weights before deciding.
How to check GSM
Factories measure GSM with a circular cutter that takes a sample of exactly 100 cm², which is then weighed. If GSM is important to your product, put the target and a tolerance (for example 320 GSM ±5%) in your specification, and ask for it to be checked on bulk fabric.
Compare actual fabrics, with their GSM, in our materials library.
