T-shirt gsm guide: what fabric weight means

What does gsm mean?

Gsm stands for grams per square metre. Take one square metre of the fabric and weigh it: a 150 gsm tee is made from fabric that weighs 150 grams per square metre. The number says nothing about the size of the T-shirt, only about how dense and substantial the material is.

That makes gsm the easiest way to compare plain T-shirts from different brands. Photos all look similar, but a tee of approx. 145 gsm and one of approx. 195 gsm feel very different in your hands.

What are light, mid and heavy T-shirts?

There is no official scale, but most shops and printers use roughly these three classes:

As a reference, well-known Fruit of the Loom tees sit across all three: Original approx. 145 gsm, Iconic approx. 150, Valueweight approx. 165 and Heavy Cotton approx. 195 gsm.

What is a heavy cotton T-shirt good for?

Heavy cotton tees of approx. 190 gsm and up have become popular for a reason. They offer a few clear advantages:

• Less see-through: especially useful for white and light colours.
• Better shape: the collar and body hold their form longer.
• A more solid look: the fabric falls straighter and looks less clingy.
• Durability: more cotton usually means a tee that survives more washes.

The downsides are that heavy tees are warmer and slightly stiffer when new. They soften with washing. If you want a white tee to wear on its own, heavy cotton is a safe choice, as explained in plain white T-shirts.

Which gsm should you choose?

A quick way to decide:

1. For hot weather, sport or as an undershirt: light, approx. 140 to 150 gsm.
2. For everyday wear, work and events: mid-weight, approx. 160 to 180 gsm.
3. For a sturdy tee worn on its own, or white that must not show through: heavy, approx. 190 gsm and up.
4. For printing: approx. 150 to 190 gsm cotton gives a good surface.

Fabric weight is one of six checks in the best plain T-shirts, alongside cotton, neckline, fit, side seams and price.

Is gsm the same as oz, and how do you convert it?

Many US brands and some UK suppliers give fabric weight in ounces instead of gsm. There are two common versions, which can be confusing:

• oz per square yard: multiply by approx. 34 to get gsm. So approx. 5 oz is roughly 170 gsm.
• oz per linear yard: an older US measure based on a strip of fabric of a set width. It gives lower numbers and cannot be converted exactly without knowing the width.

When in doubt, look for the gsm figure, which is standard in Europe and much easier to compare. A rough conversion table for oz per square yard:

Also remember that a stated gsm is usually measured before washing and can vary slightly between colours and batches. Treat it as a guide, not an exact figure.

Is gsm the only thing that matters for quality?

No. Two tees with the same gsm can feel different depending on the cotton, the yarn and the knit. Look at these points too:

• Fibre: 100 % cotton is soft and breathable. Heather colours contain some polyester.
• Collar: a ribbed neckline that springs back after stretching.
• Construction: classic Fruit of the Loom tees are tubular, with no side seams.
• Care: cotton can shrink a few percent on a hot first wash, regardless of weight.

Where can you buy plain cotton tees by weight?

At Marmalade Co. plain Fruit of the Loom T-shirts cost €6.95, or €6.26 each from 5 pieces, in 15 colours from XS to XXXL. Long sleeve tees and sweatshirts are available if you want something warmer. DHL delivery is €7 flat to Ireland and 10 EU countries (Austria, Belgium, Finland, France, Germany, Italy, the Netherlands, Poland, Portugal and Spain). The shop does not currently deliver to the United Kingdom.

Buying for a group? See plain T-shirts in bulk for totals and size splits.