What GSM Means in Clothing, and Why It Matters
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Every Gilded Streets product page states a GSM figure. Most brands in this category do not. This is what the number means, and what it does not mean.
What GSM means
GSM stands for grams per square metre. It is the weight of one square metre of a fabric. A 260 GSM cotton jersey weighs 260 grams per square metre. A 530 GSM cotton fleece weighs about twice that.
GSM describes density, not thickness and not quality. Two fabrics can share a GSM figure and feel completely different depending on the fibre and the knit.
How fabric weight is measured
A cutting die takes a disc of known area from the finished fabric. The disc is weighed, and the result is scaled to one square metre. Some brands publish the same figure in ounces per square yard instead. The two Vintage Wash pieces in our catalogue carry both: 390 GSM and 11.5 oz/yd². To convert roughly, divide GSM by 33.9.
The figure is taken from finished fabric, after washing and dyeing. This matters for washed garments, where the process changes the hand of the cloth.
Lightweight, midweight, heavyweight
There is no governing body for these terms. Used consistently, they break down roughly as follows.
- Under 180 GSM. Lightweight. Summer tees, base layers. Drapes close, dries fast, shows the body underneath.
- 180 to 280 GSM. Midweight. The range most retail tees sit in.
- 280 to 400 GSM. Heavyweight. Structured tees, lighter fleece, transitional layers.
- 400 GSM and above. Ultra-heavyweight. Dense fleece, winter hoodies, garments that hold a shape on their own.
Our catalogue runs from 200 GSM to 530 GSM. Nothing we make sits in the lightweight band.
What changes when GSM increases
Structure. Heavier cloth holds its own shape. A 530 GSM hoodie stands away from the body at the shoulder. A 210 GSM knit follows it.
Drape. Lighter fabric falls in soft folds. Heavier fabric falls in fewer, larger ones. This is why oversized cuts are usually built in heavier cloth. The weight is what stops volume reading as sloppiness.
Warmth. More material means more trapped air. Fibre matters here too. Cotton insulates well and holds moisture; synthetics insulate less but dry faster.
Durability. Denser knits generally resist abrasion and pilling better than open ones. Weight alone does not guarantee this. Yarn quality and knit construction do most of the work.
Drying time. This is the real cost of weight. A 530 GSM cotton hoodie takes considerably longer to dry than a 350 GSM blend. Cotton compounds it, since cotton holds more water than polyester.
Seasonal comfort. Above roughly 400 GSM, a garment becomes a cold-weather piece. Below 300 GSM it works most of the year.
Is higher GSM always better?
No, and it is worth being direct about that.
A 530 GSM hoodie is the wrong garment for a mild October afternoon. It is slow to dry, it does not pack down, and it will not layer under a jacket without bulk. A 350 GSM piece will be more useful more often for most people.
Weight is a specification, not a verdict. It tells you what a garment is for. Our 200 GSM cargo pant is not a lesser product than our 530 GSM hoodie. It is a different one, built for different weather.
What weight does do is make a garment comparable. A stated number can be checked. Adjectives cannot.
GSM and cotton
Cotton behaves differently from blends at the same weight. It is heavier for its bulk, it softens with washing, and it holds moisture. A 400 GSM pure cotton hoodie feels denser in the hand than a 400 GSM cotton-polyester blend, and takes longer to dry.
Our pure cotton pieces include the Heavyweight Cotton Hoodie at 530 GSM, the Acid Wash Oversize Hoodie at 420 GSM, and the Mineral Wash Crop Hoodie at 400 GSM. Blended fleece pieces such as the Vintage Wash Boxy Fleece Hoodie at 390 GSM sit lower in weight but carry polyester, which changes how they dry and how they hold colour through a wash.
GSM and hoodies
Hoodies show weight more clearly than any other garment, because there is more fabric involved. Our hoodies run from 350 GSM to 530 GSM.
Below 300 GSM a hoodie tends to collapse at the shoulder. Between 350 and 400 GSM it holds structure while staying wearable across seasons. Above 450 GSM it becomes a genuine winter piece.
We cover this in more detail in What Makes a Hoodie Heavyweight, publishing in the Journal on 15 September 2026.
GSM and T-shirts
The range is narrower and the differences are easier to feel. Our tees run from 210 GSM to 340 GSM.
The Turtleneck Batwing Tee is 210 GSM in a cotton-elastane knit, cut to follow the body. The Premium Heavyweight Tee is 260 GSM combed cotton with a reinforced collar. The Snow Wash Raw Hem Boxy Tee is 340 GSM pure cotton and holds a boxy line without help.
Around 280 GSM a tee stops being underwear-adjacent and starts being outerwear. The collar stops rolling, the hem stops curling, and the shoulder seam stays where it was cut.
400 GSM versus 500 GSM
A hundred grams per square metre sounds small. In a full hoodie it is not.
At 400 GSM a hoodie is structured and warm and still wearable indoors. At 500 GSM and above it becomes a coat replacement. It will not layer under anything slim, and it will take most of a day to air dry.
The full comparison, using our 400 GSM and 530 GSM pieces, is in 400 GSM vs 500 GSM Hoodies, publishing in the Journal on 1 October 2026.
How to compare clothing using GSM
Weight on its own is not enough. Three numbers together tell you most of what you need.
- GSM. How dense is the cloth.
- Fibre composition. Stated as percentages. 100% cotton behaves differently from 53% polyester at the same weight.
- Construction. Jersey, fleece, French terry. Our Acid Wash Oversize Sweatshirt is 360 GSM French terry, which reads differently from a brushed fleece at the same weight.
If a brand publishes none of these, you are buying on adjectives. A garment described only as premium, luxury, or heavyweight has told you nothing you can check.
Our approach to publishing this data is set out on the Materials page, and the reasoning behind it on Brand Philosophy.
The Gilded Streets GSM range
Verified figures across the current catalogue.
| Category | GSM range |
|---|---|
| Pants and cargos | 200 to 365 |
| Performance | 210 to 300 |
| T-shirts | 210 to 340 |
| Shorts | 250 to 500 |
| Jackets and outerwear | 340 to 440 |
| Sweatshirts and crewnecks | 360 to 420 |
| Hoodies | 350 to 530 |
| Sweatpants | 350 to 530 |
Every figure appears on the relevant product page. Pieces at 400 GSM and above are described as heavyweight, and those at 500 GSM and above as ultra-heavyweight.
How these fabrics are finished, washed, and constructed is covered on Craftsmanship.
Frequently asked questions
What does GSM mean in clothing?
Grams per square metre. It is the weight of one square metre of the finished fabric, and it describes how dense the cloth is.
What does 300 GSM mean?
One square metre of that fabric weighs 300 grams. In a T-shirt this is heavyweight, structured enough to hold a boxy shape. In a hoodie it is on the light side.
What does 500 GSM mean?
One square metre weighs 500 grams. In a hoodie or sweatpant this is ultra-heavyweight, a genuine cold-weather garment that holds its own shape.
Is higher GSM better?
No. Higher GSM means denser and warmer, and also slower to dry and harder to layer. The right weight depends on the season and how you intend to wear the piece.
What GSM is a heavyweight hoodie?
Commonly 350 GSM and above. Above 450 GSM most people would call it ultra-heavyweight. Our hoodies run from 350 to 530 GSM.
Does GSM tell you the quality?
No. It tells you the weight. Fibre composition, yarn quality, and knit construction determine how a garment wears. GSM is one input of several.