What Is GSM in Fabric? A Simple Guide for Garment Manufacturers

GSM means grams per square metre. Learn how to measure fabric GSM, which GSM suits shirts, t-shirts, kurtis, uniforms and denim, and how GSM affects price.

11/1/20265 min read

Quick answer: GSM stands for grams per square metre. It is the weight of one square metre of fabric. A higher GSM means a heavier, usually thicker fabric; a lower GSM means a lighter, often more breathable one. Most shirting is 100–140 GSM, t-shirts 160–220 GSM, sweatshirts 260–350 GSM, and denim around 270–475 GSM (8–14 oz).

If you buy fabric in bulk, GSM is the one number that appears on almost every quote, swatch card and invoice. Getting it right decides how a garment drapes, how it feels on the skin, how long it lasts and how much it costs. This guide explains GSM in plain language so you can order with confidence.

How GSM is measured

GSM is measured with a simple tool called a GSM cutter (a round die that cuts exactly 100 square centimetres) and a precision scale.

Cut a sample with the GSM cutter from the body of the fabric, not the edge (selvedge).
Weigh the sample in grams.
Multiply by 100. A 1.4 g sample means 140 GSM.

Mills normally test three to five samples from across the width and take the average, because weight can vary slightly from the selvedge to the centre. If you don't have a cutter, you can cut a precise 10 cm × 10 cm square with scissors and a ruler and do the same calculation — less accurate, but useful for a quick check.

Fabric GSM chart: what weight suits which garment?

Garment	Typical GSM	Common fabrics
Linings, scarves, dupattas	40–90	Georgette, chiffon, voile, light polyester
Shirts and blouses	100–140	Cotton poplin, poly-cotton, gingham, yarn-dyed stripes
Kurtis and dresses	110–160	Rayon, polyester crepe, cotton cambric
T-shirts	160–220	Single jersey cotton, poly-cotton knit
Trousers and uniforms	200–280	PV suiting, twill, gabardine
Sweatshirts and hoodies	260–350	Fleece, loopknit
Jeans and jackets	270–475	Denim (8–14 oz)

These ranges are starting points. A fashion brand may deliberately pick a heavier 180 GSM tee to feel premium, or a 95 GSM shirt for a summer collection.

GSM vs ounces (oz)

Denim and some imported fabrics are sold in ounces per square yard instead of GSM. To convert:

GSM = oz × 33.906
oz = GSM ÷ 33.906

So 10 oz denim is about 339 GSM, and 12 oz is about 407 GSM. We explain this in more detail in our denim weight guide.

Does higher GSM mean better quality?

Not always. GSM tells you weight, not quality. Two fabrics with the same GSM can perform very differently depending on:

Fibre: 140 GSM cotton and 140 GSM polyester feel completely different.
Yarn count: finer yarns packed tightly can give a smooth, strong fabric at a lower GSM.
Weave or knit: a twill and a plain weave at the same GSM drape differently.
Finish: mercerising, peaching or resin finishes change feel and weight.

A heavier fabric is usually more durable and less see-through, but it can also be hotter and costlier. The right GSM is the one that matches the garment, the season and your price point.

How GSM affects fabric price

Because heavier fabric contains more yarn, price per metre rises with GSM. As a rough rule, moving from 120 GSM to 160 GSM in the same quality adds 15–30% to the cost. Width matters too: a 60-inch fabric at 140 GSM weighs more per running metre than a 44-inch fabric at the same GSM.

When comparing quotes, always check that suppliers are quoting the same GSM, width and fibre. A cheap quote is sometimes cheap because the GSM is quietly lower.

GSM tolerance: what is acceptable?

No fabric is perfectly uniform. Most mills work with a tolerance of ±3–5%. For a 140 GSM order, that means 133–147 GSM is normally acceptable. Agree on the tolerance in writing before production, especially for uniforms or repeat orders where consistency matters.

Common GSM mistakes buyers make

Ordering by feel alone. A swatch that feels "thick" might be a low-GSM fabric with a bulky finish. Ask for the measured number.
Ignoring shrinkage. Fabric GSM increases slightly after washing as it shrinks. Test a washed sample too.
Mixing knit and woven expectations. A 180 GSM knit is a normal t-shirt; a 180 GSM woven is a heavy shirting.
Not checking every lot. GSM can drift between dye lots. Test the first and last rolls.

Quick checklist before you order

Write the target GSM and tolerance (for example 140 ± 4%).
Confirm fibre, width (44", 58" or 60") and finish.
Request a swatch and test its GSM yourself.
Ask for test results for shrinkage and colour fastness.
Check GSM again on delivery.

Frequently asked questions

What GSM is good for a cotton shirt?
100–140 GSM is standard. Go lighter (90–110) for summer shirts and heavier (130–150) for oxford or casual shirting.

What GSM is best for t-shirts?
160–180 GSM for everyday tees, 180–220 GSM for premium or oversized fits.

Is 200 GSM fabric thick?
For a woven shirt fabric, yes. For a knitted t-shirt, 200 GSM is a medium-heavy, good-quality weight.

What is the GSM of polyester fabric?
EVOMODA's 100% polyester ranges from 120 to 240 GSM, woven or knitted, in 58" or 60" width.

Need fabric at a specific GSM? EVOMODA supplies denim, polyester, crepe, gingham and stripe fabric in bulk from Delhi. Send your fabric type, GSM, colour and quantity to contact@evomoda.website or WhatsApp +91 83688 83484.