What GSM actually measures
GSM is grams per square metre. It is the weight of one square metre of the fabric, and it is the single most useful number you can know about a hoodie before you touch it.
It is not a quality score. A 500 GSM fleece is not "better" than a 280 GSM loopback — it is heavier, warmer, stiffer and more expensive, and for a summer drop in Sydney it would be the wrong choice. GSM tells you what a garment will feel like and how it will behave. Nothing more, and nothing less.
Two garments at the same GSM can still differ, because weight is not the only variable. Fibre content, knit construction and finishing all change the hand feel. But if someone tells you one number about a hoodie, GSM is the one to ask for.
The weights, and what each one is for
250 GSM — lightweight
Layering weight. Soft, breathable, and closer to a heavy sweatshirt than to what most people picture when they hear "hoodie". Good for warmer climates, for summer drops, and for pieces meant to sit under a jacket rather than over a t-shirt.
The trade-off is structure. At 250 the fabric drapes rather than holds, so an oversized cut will hang soft instead of standing away from the body.
300 GSM — midweight
The versatile everyday option, and the weight most high-street hoodies sit at. Warm enough for three seasons in the UK, light enough not to feel like outerwear. If you have no strong opinion and no particular use case, this is the safe answer.
350 GSM — midweight, and the streetwear default
A popular choice for streetwear, and for good reason. It has visible substance without being heavy to wear, it holds an oversized silhouette reasonably well, and it takes print and embroidery cleanly.
If you are launching a first hoodie and want it to feel like a considered product rather than a blank, this is the weight most brands land on.
400 GSM — heavyweight
Premium feel and real structure. The garment starts to hold its own shape: shoulders sit where the pattern puts them, the body falls straight rather than clinging, and a boxy cut reads as deliberate.
This is where "heavyweight hoodie" as a selling point genuinely starts to mean something.
450 GSM — heavyweight, built for oversized
Ideal for oversized and winter styles. At this weight the fabric carries a dropped shoulder and a wide body without collapsing, which is exactly the silhouette most streetwear brands are after.
Worth knowing: heavier fabric makes every construction decision more visible. A poorly set hood or an under-specified rib shows up more at 450 than at 300.
500 GSM — ultra heavyweight
Maximum warmth and durability. Substantial, structured, and unmistakably a heavy garment when picked up — which is often the point.
Two honest cautions. It is warm enough to be uncomfortable indoors, and it costs meaningfully more, both in fabric and in freight, because weight is what you pay to ship.
Fleece against French terry
GSM tells you the weight. Construction tells you the feel, and the two are independent.
French terry has uncut loops on the inside. It is smoother, more breathable and quicker-drying, and it holds its shape well over time. Loopback is the same idea by another name.
Brushed-back fleece is French terry whose loops have been brushed open into a soft, fuzzy pile. It is warmer and softer against the skin, and it is what most people mean by "hoodie fabric".
The trade-off is pilling. A brushed surface is a disturbed surface, and cheaper brushed fleece pills faster than the equivalent loopback. Our streetwear fabric guide covers the fabrics we actually run; the fabric types glossary covers the wider vocabulary including the fibre-against-construction distinction.
Composition
Most hoodie fleece is cotton-rich with some polyester. Higher cotton means better hand feel, more breathability and more shrinkage. More polyester means better shape retention, faster drying and a slicker surface that some prefer and some do not.
A small percentage of elastane appears in fitted styles and almost never in oversized ones.
What GSM does to your garment
Drape and silhouette
Lighter fabric follows the body; heavier fabric resists it. If your design depends on a boxy, structured shape, going too light will quietly undo it no matter how good the pattern is.
Hood weight
A hood is the heaviest single component on a hoodie, and at 450 or 500 GSM a double-layer hood becomes genuinely heavy. It can pull the neckline back when worn down. This is a real construction decision, not a detail — single-layer hoods exist for a reason at the top of the weight range.
Rib
Cuffs, hem and sometimes the pocket trim are ribbed. The rib should be specified to suit the body fabric: a light rib on a 450 GSM body looks and feels wrong, and stretches out faster.
Print and embroidery
Heavier, more textured fabric is harder to print crisply — a brushed 450 GSM surface will not hold fine detail the way a smooth 280 GSM loopback will. Screen printing on heavy fleece usually needs a thicker deposit or an underbase.
Embroidery is the opposite: it sits better on a substantial fabric, and on very light fleece it can pucker without a backing.
Shrinkage
Cotton shrinks. Heavier cotton has more to shrink. Fabric should be pre-shrunk before cutting, and if it is not, your size Large becomes a Medium after the customer's first wash. Ask.
Seasonality
250–300 for spring and summer, 300–400 for three-season wear, 400–500 for autumn and winter. Most brands running a single hoodie year-round land at 350 to 400 because it is the least wrong answer in every season.
Choosing a weight for your brand
Three questions, in order.
Where do your customers live? A brand selling into Australia and one selling into northern Europe should not be running the same weight.
What silhouette are you making? Oversized and boxy needs weight to work. Fitted does not.
What are you decorating with? Fine detail print pushes lighter and smoother; heavy embroidery and puff print reward substance.
And then the thing that resolves all three: hold the fabric before you commit. A sample is made before any bulk run for exactly this reason, and swapping the weight after handling the first sample is normal rather than a failure. How minimum order quantities work explains what a run costs to start, and cut and sew manufacturing covers what happens between choosing a fabric and receiving the garments.
If you want a hoodie made to a weight you have chosen rather than one a wholesaler happened to stock, that is what custom hoodie manufacturing is for.
