Industry Guides

What GSM Means in Workwear (And Why It Matters For Summer)

9th September 2026

Pick up two polo shirts that look identical, and one will feel noticeably heavier than the other. Same style, same colour, possibly the same brand - but a completely different weight in your hands. That difference usually comes down to GSM, and in summer workwear, it’s something to pay attention to.

Understanding GSM won’t turn you into a fabric expert, but it will help you make better purchasing decisions when keeping a team comfortable, productive, and presentable through a full shift in the heat.

Man on the left is wearing a brown polo shirt with glasses and the man on the right is wearing a blue polo shirt.

What Does GSM Mean?

GSM stands for grams per square metre. It’s the standard measurement that describes the weight of a fabric. Specifically, it’s how much one square metre of it weighs in grams. The higher the number, the heavier and usually thicker the fabric. The lower the number, the lighter and more open the weave.

It’s one of the most useful figures on a product specification because it gives you an objective indication of weight before you’ve touched the garment. A polo listed at 170gsm and one listed at 220gsm might look similar in a product image, but they’ll behave very differently in warm weather.

Low vs High GSM: What’s the Difference?

The GSM scale runs from around 80gsm at the lightest end for fine summer tees, up to 400gsm or more for heavyweight fleeces and winter jackets. For everyday workwear, the range sits broadly between 140gsm and 300gsm.

Low GSM (roughly 140-180gsm)

This range produces a lighter, more open fabric that allows air to circulate and heat to escape. Garments feel noticeably less substantial, which is exactly the point - they’re designed for warmth to be a non-issue.

Mid GSM (roughly 180-240gsm)

For general-purpose workwear, this is the most common range. Polos, sweatshirts, and standard-issue t-shirts tend to sit here. The fabric has enough body to hold its shape through washing and daily use, without feeling heavy.

High GSM (240gsm and above)

This is where you find durability-led garments like heavyweight hoodies, fleeces, and outerwear. These fabrics retain heat, so they’re ideal for autumn and winter, but counterproductive in the summer.

Why GSM Matters in Summer Workwear

In warm weather, fabric weight directly affects how the body regulates temperature. A heavier fabric traps heat against the skin, restricts airflow, and holds moisture. All of these make a long shift significantly more uncomfortable.

Heat management

A lower GSM fabric creates more space within the weave for air to move. On a warm site or in a warehouse without adequate ventilation, the difference in airflow between a 160gsm polo and a 240gsm one is noticeable by mid-afternoon.

Comfort and productivity

Physical discomfort is a distraction. Workers in heavy, warm clothing in the heat slow down, lose concentration sooner, and fatigue faster. Switching to a lighter garment for summer is a straightforward way to support performance through the warmer months.

Sweat and airflow

Heavier fabrics hold moisture against the skin rather than releasing it. A lower GSM garment combined with the right fabric allows sweat to evaporate rather than accumulate, keeping workers drier and more comfortable.

Recommended GSM for Summer Workwear

These are guidelines rather than fixed rules, but a useful starting point when comparing products. The right choice also depends on fabric type and demands of a role.

T-shirts: 140-170gsm. At this weight, a t-shirt is lightweight without feeling insubstantial. Anything above 180gsm starts to feel too warm in summer conditions.
Polo shirts: 160-200gsm. Polos need a little more structure than t-shirts to hold their collar and keep their shape through washing, so a slightly higher GSM is advisable. A 170-185gsm polo is a good summer target for most work environments.
Workwear trousers: 200-240gsm. Trousers need to be more durable than tops, so a slightly higher GSM is appropriate, even in summer. Look for fabrics at the lower end of this range combined with a looser cut to support airflow.
Shorts: 180-220gsm. Where shorts are allowed, a fabric in this selection is both durable and comfortable in warm weather.

Other Factors Beyond GSM

GSM tells you about weight, but that alone doesn’t determine how a garment performs in summer. Fabric composition matters just as much.

Cotton vs polyester blends

Cotton is naturally breathable and soft against the skin, which makes it a reliable fabric for hot weather working. An 180gsm cotton polo will typically feel cooler than a 160gsm polyester polo, because polyester traps heat more readily.

For summer workwear, garments with a higher cotton percentage — or 100% cotton — often fare better in warm conditions. Polycotton blends (typically 65% polyester, 35% cotton) offer a compromise between durability and breathability, and are widely used in workwear ranges.

Moisture-wicking fabrics

Performance fabrics designed to draw sweat away from the skin and allow it to evaporate are a consideration for physically active roles. They’re usually polyester-based, but engineered differently from standard polyester. The fibre structure is designed to move moisture outward rather than hold it.

For construction workers, warehouse operatives, and anyone in a physically demanding role, moisture-wicking garments can make a real difference through a summer shift.

Fit and ventilation

A lower GSM garment in a close-fitting cut can still feel uncomfortable in the heat if it restricts airflow. Where safety requirements allow, a looser cut at the same GSM will feel noticeably cooler because air can circulate between the fabric and skin. This is particularly relevant for trousers and base layers worn under PPE.

Choosing the Right Summer Workwear by Industry

The right GSM for summer workwear isn’t one-size-fits-all. Different working environments place different demands on the garments.

Construction and outdoor trades

Construction workers on site in summer face both heat and physical hazards, which means the garment should be robust enough to fit the job. A 170-185gsm polycotton polo or t-shirt works well here. It’s light enough for comfort and durable enough for the environment.

Hi-vis requirements don’t go away in summer, but lightweight open-weave hi-vis vests worn over a lighter base layer are a more comfortable combination than heavier hi-vis garments worn alone.

Warehousing and logistics

Warehouses and distribution centres trap heat, and workers in these environments are typically on their feet moving for the full shift. A lightweight 160-180gsm t-shirt or polo in a moisture-wicking fabric is the right starting point. Shorts may be appropriate if the site’s policy and relevant safety considerations allow.

Hospitality and catering

Front-of-house staff need to look presentable through a full service, which means choosing garments that hold their shape even as temperatures rise. A 180-200gsm polo in a cotton-rich fabric tends to work well. It’s structured enough to look the part, but light enough not to become uncomfortable by the end of a long shift.

Kitchen environments involve their own ventilation challenges, and lightweight chefswear designed for high-heat kitchens serves a different function than general hospitality uniforms.

Office and corporate environments

Air conditioning changes the calculation somewhat for office workers. A garment that’s comfortable walking between sites in summer heat may be too light for a cool office. An 180-210gsm polycotton polo or short-sleeved shirt gives enough structure for a professional appearance while remaining comfortable in warmer conditions outside.

Man on the left is wear a dark navy polo shirt and the woman on the right is wearing a deep red polo shirt.

Finding the Right Summer Workwear

GSM is a straightforward figure that often gets overlooked when businesses order uniforms. For most of the year, it makes little practical difference, but in summer, a team in 240gsm polos will feel the difference compared to one in 170gsm garments. And it will show up in how they feel and perform by the end of the working day.

The product specification on every garment in the MyWorkwear range includes the GSM, fabric composition, and where relevant, any moisture-wicking or performance properties. This means you can compare options on the details that matter, not just the price.

Shop our summer workwear range or contact us for guidance on the best products for your team.

Here at MyWorkwear, we have been proud suppliers of personalised workwear since 1976.

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