Fabrics
Hoodie GSM Guide: What Fabric Weight Actually Means
280, 320, 400 gsm — the number every supplier quotes and few buyers question. Here's what it measures, what it changes in production, and how to pick the right weight for your market.
August 11, 2026 · 11 min read
Table of Contents
1. What GSM Actually Measures
GSM means grams per square meter — the weight of a one-meter-square piece of fabric. A 320 gsm fabric means every square meter weighs 320 grams. That's all it is: a measure of how much fiber is packed into the cloth.
What it is not: a direct measure of thickness, warmth, or quality. A dense 320 gsm french terry and a loosely brushed 320 gsm fleece can feel completely different in the hand, because construction changes everything — more on that in section 3.
How suppliers check it: cut a 10 cm × 10 cm swatch with a round cutter, weigh it on a precision scale, multiply by 100. You can do the same with any sample that lands on your desk — a $15 fabric scale and two minutes of math tells you whether "400 gsm heavyweight" is real or marketing.
2. The Four Weight Classes
Hoodie fabrics cluster into four bands. Names vary between suppliers, but the behavior is consistent:
| Class | GSM range | Hand feel & drape | Best for |
|---|---|---|---|
| Lightweight | 200–260 | Soft, drapey, closer to a thick tee | Spring/summer drops, warm climates, layering pieces, fashion fits |
| Midweight | 280–340 | The "standard" hoodie — balanced body and softness | Year-round retail, most DTC brands, unisex basics |
| Heavyweight | 340–400 | Structured, holds its shape, premium hand | Streetwear, oversized fits, autumn/winter, higher price points |
| Ultra-heavy | 400+ | Boxy, armor-like, minimal stretch | Luxury streetwear, statement pieces, cold climates |
Two things to notice in the table. First, the jump from 280 to 400 gsm is a jump of over 40% in fabric weight per garment — you feel it instantly, and so does your costing sheet. Second, "heavyweight" as a marketing word starts around 320 gsm in most catalogs, so always ask for the number, not the adjective.
3. GSM Isn't Everything: French Terry vs Fleece
Two hoodies at identical 320 gsm can wear like different products, because GSM says nothing about construction or fiber:
French terry (loopback) — unbrushed loops on the inside, smooth face outside. Breathes better, drapes cleaner, resists pilling. The default for midweight and warm-climate hoodies.
Fleece (brushed) — the inside loops are sheared and brushed into a soft pile. Warmer and softer against skin, but cheaper brushed fleece pills fast. The default for heavyweight and winter hoodies.
Fiber mix — 100% cotton feels premium and prints beautifully but costs more and shrinks more. CVC (chiefly cotton, ~80/20) keeps most of the hand feel with better stability and price. TC (poly-dominant) is budget territory. Same GSM, very different garment.
Specify "400 gsm" alone and a factory can hit the number with a loose, cheap knit that feels like cardboard. Specify "400 gsm brushed fleece, 100% cotton, compacted" and you've described an actual product.
For a closer look at the fabric choice beyond weight, use our French terry and brushed fleece sample comparison.
4. What Weight Changes in Production
Fabric weight ripples through the whole order, not just the feel:
- Unit cost. Fabric is priced by weight. Moving from 280 to 400 gsm adds roughly 40% more fabric per hoodie — expect the fabric line of your quote to grow by a similar share.
- Shrinkage. Heavier cotton knits hold more residual tension. Without compaction or a garment wash, a 400 gsm 100% cotton hoodie can shrink visibly after the first wash. Ask for pre-shrunk (compacted) fabric, or build wash testing into sampling.
- Decoration. Heavyweight fabric is a better canvas: embroidery sits cleaner, puff print keeps its edge, appliqué lies flatter. Lightweight fabrics need backing and gentler artwork. If your design language is heavy graphics, weight is your friend.
- Washes and dyes. Garment dye, enzyme and snow washes read much better on 340+ gsm — the color depth and fade patterns simply have more material to work with.
- Shipping. Fifty 400 gsm hoodies weigh roughly a third more than fifty 280 gsm ones. At sea freight rates it's noise; at express sample rates you'll notice it.
5. Choosing by Market and Season
The right GSM is a positioning decision before it's a technical one:
| Your situation | Suggested GSM | Why |
|---|---|---|
| First drop, testing a design | 280–320 | Stock fabrics widely available, lower unit cost, safe year-round weight |
| Streetwear / oversized fit | 340–400 | Structure is the whole point — customers expect the hand feel |
| Warm climate or spring/summer | 200–280 | Drape and breathability beat bulk |
| Winter / cold markets | 360–400 brushed | Brushed back traps warmth; pairs with garment dye well |
| Luxury statement piece | 400+ | The weight itself is the selling point |
| Heavy graphic / embroidery focus | 340+ | Decoration sits cleaner on a stable, heavy base |
If you're split between two weights, order the sample in the heavier one — it's easier to imagine lighter than to imagine heavier.
6. How to Specify GSM in Your Tech Pack
One line in a tech pack saves weeks of argument. A complete fabric weight spec has four parts:
- Target GSM with tolerance — "320 gsm ±5%", not just "320 gsm". Knitted fabric varies by lot; a tolerance keeps the conversation factual.
- Construction — french terry or brushed fleece, and the face finish you expect.
- Composition — 100% cotton, CVC 80/20, or another blend.
- State after wash — specify whether GSM is measured greige, after dyeing, or after garment wash. Washed garments read slightly different weights.
Then verify at two gates: approve the fabric hand-feel sample before cutting, and weigh the proto sample when it arrives. Both take minutes and both are standard practice — any factory doing AQL 2.5 inspection already weighs fabric per lot.
If you don't have a target yet, start from a reference: send a hoodie you love and ask the factory to match its weight and construction. That's faster than guessing numbers, and it's how most first orders actually start. Our fabric sourcing guide covers the wider material landscape beyond fleece.
FAQ
Is higher GSM always better?
No. Higher GSM means more fabric, more cost, more warmth, more structure — whether that's "better" depends on your market and season. A 450 gsm hoodie is a great winter statement and a terrible summer product.
What GSM do most streetwear brands use?
Most established streetwear hoodies sit between 320 and 400 gsm brushed fleece. Below 300 reads as a basic; above 400 is a deliberate luxury choice.
How much does GSM affect the price?
Fabric is roughly half the garment cost and is priced by weight, so the effect is close to linear: 400 vs 280 gsm adds around 40% to the fabric portion. Trims, labor and decoration stay roughly the same.
How can I verify the GSM myself?
Cut a 10 cm × 10 cm square from an inconspicuous area, weigh it in grams on a kitchen scale, multiply by 100. It won't be lab-grade, but it catches any serious discrepancy.
Can I order a custom GSM that isn't in the stock range?
Yes — mills can knit to your spec, but custom-knit fabric carries its own minimums (usually a few hundred kilograms). Below that, stock 320/350/400 gsm fabrics are the practical route.
Planning a hoodie line?
Tell us your target weight, fabric and quantity — we'll quote stock and custom-knit options side by side, MOQ from 50 pcs.
Get a Free Quote →