GSM — grams per square metre — is how fabric weight is measured. It is one of the first things a buyer specifies, because it drives how a garment looks, feels and performs. Here is what GSM means and how yarn choice affects it.
What GSM tells you
GSM is simply the weight of one square metre of fabric. Higher GSM means heavier, thicker, warmer fabric; lower GSM means lighter and more breathable. A summer t-shirt might be 140–160 GSM; a winter fleece 280–350 GSM.
Typical GSM ranges
| Fabric | Typical GSM |
|---|---|
| Light t-shirt jersey | 120–160 |
| Standard t-shirt | 160–200 |
| Polo pique | 180–220 |
| Sweatshirt / fleece | 250–350 |
How yarn count affects GSM
Coarser yarn (lower Ne) and tighter knits raise GSM; finer yarn (higher Ne) and looser knits lower it. So GSM is a product of yarn count, stitch length and construction together — which is why matching the right count to your target GSM matters.
Working to a target GSM? Use our fabric weight converter and yarn count converter, or tell us your fabric on our contact page and we will recommend the count. AA Enterprises, since 1974.