What Is GSM in Fabric? GSM Chart for T-Shirts, Hoodies, Shirts & More
GSM is one of the first numbers you see on any fabric quote, and one of the most misunderstood. Buyers ask for “a heavy tee” or “a thick hoodie” without a number, factories quote different fabrics under the same name, and the sample arrives feeling nothing like the brief. Understanding GSM fixes most of that. This guide explains what GSM means, how it is measured, what typical values look like for common garments, and why weight alone does not tell you whether a fabric is good.
What Does GSM Mean?
GSM stands for grams per square metre. It is the weight of one square metre of fabric, so a 200 GSM fabric weighs 200 grams per square metre. It is the standard way to describe how heavy a fabric is, and it is used for knits (T-shirts, hoodies) and wovens (shirts, trousers) alike. In the US you will also see ounces per square yard (oz/ydΒ²). To convert, multiply oz/ydΒ² by about 33.9 to get GSM. For example, a 10 oz/ydΒ² fabric is roughly 340 GSM.
How GSM Is Measured
Mills and labs cut a circular sample of a known area, often 100 cmΒ², weigh it on a precision scale and calculate GSM from the result. Standard test methods exist for this, and a good factory will test the fabric before cutting. When you approve a sample, ask for the measured GSM of the finished fabric, not only the weight the supplier quoted for the raw cloth, because finishing steps such as washing, brushing and compacting can change it.
GSM Chart: Typical Weights by Garment
| Garment | Lightweight | Mid-weight | Heavyweight |
|---|---|---|---|
| T-shirt (jersey) | 120β160 GSM | 170β200 GSM | 220β300 GSM |
| Polo (pique) | 150β190 GSM | 200β240 GSM | 250+ GSM |
| Hoodie / sweatshirt (fleece or terry) | 240β280 GSM | 280β350 GSM | 400β500+ GSM |
| Shirting (woven cotton) | 90β120 GSM | 120β160 GSM | 160+ GSM |
| Trousers (twill or drill) | 180β220 GSM | 220β300 GSM | 300+ GSM |
| Denim | 200β280 GSM | 280β340 GSM | 340+ GSM |
These are common industry ranges, not rules. Different mills and markets use different labels for “light” and “heavy”, so always agree the actual number with your supplier.
Heavier Does Not Always Mean Better
GSM tells you how much fabric is in a square metre, not how good it is. Two fabrics at 200 GSM can feel completely different depending on the fibre, the yarn quality, how tightly it is knitted or woven and how it is finished. A cheap, coarse 220 GSM tee can feel worse than a fine, combed 180 GSM one. Read our guides on combed vs carded cotton and handfeel to see the other variables.
What GSM Changes in Your Product
- Warmth and season: lighter fabrics suit summer, heavier ones suit winter. See our winter fabrics guide.
- Drape and structure: light fabrics drape and cling, heavy ones hold shape, which is why boxy streetwear uses heavy terry. See our heavyweight hoodie guide.
- Opacity: very light fabrics, especially in white, can be see-through.
- Durability: heavier fabrics generally last longer, if the quality is good.
- Cost and shipping: more GSM means more yarn per garment and higher freight weight, so price rises with weight.
How to Choose the Right GSM
- Start with the climate and season your customer will wear it in.
- Pick the feel you want: soft and flowing, or structured and substantial.
- Check your price point. Heavier fabric raises cost, so confirm customers will pay for it.
- Compare against a reference garment you already like and ask the factory for its measured GSM.
- Test a washed sample before bulk, because GSM and feel can change after the first wash.
Putting GSM on a Tech Pack
Always write GSM with its tolerance, for example “280 GSM, Β±5%”, together with composition, knit or weave type and finish. Without a tolerance, the factory has no way to know what range is acceptable. Our step-by-step tech pack guide shows where this goes, and our GSM guide for kids’ shirts applies the same idea to children’s wear.
Frequently Asked Questions
What is a good GSM for a T-shirt?
Most everyday tees sit between 160 and 200 GSM. Premium or heavyweight tees go to 220β300 GSM, and very light summer tees go below 160.
What GSM is a heavyweight hoodie?
Standard hoodies are about 280β350 GSM. Heavyweight styles are usually 400 GSM and above.
Is higher GSM more expensive?
Usually yes, because more yarn is used per metre and the garment weighs more to ship. The fibre and finish also affect price.
Can I request a specific GSM for my order?
Yes, within what the fabric supplier can provide. Tell us your target GSM and fabric type, and we’ll confirm availability. Sampling starts from a 1-set MOQ and production from around 50 pieces per style.
Need help choosing a fabric weight? Start your private label project or send a wholesale inquiry with the garment and feel you want.