What Weight Suit Fabric Do You Need in Australia?

The short answer

What GSM actually means

GSM is the weight of one square metre of cloth. A higher number means a heavier, denser fabric.

• Under 220 GSM. Tropical weight. Breathable, packs badly, creases readily. Right for genuine heat and humidity.
• 220 to 250 GSM. Lightweight. Comfortable in warm weather, still holds a line. The standard for Australian summer weddings.
• 250 to 300 GSM. Mid weight. The year-round workhorse for most of Australia. If you own one suit, own this.
• 300 to 340 GSM. Heavy. Winter weight, holds structure beautifully, drapes properly. Too warm above the low twenties.
• Over 340 GSM. Overcoating and heavy tweed. Rare in Australian suiting outside Tasmania and the alpine regions.

Weight is not the same as quality. A 220 GSM Loro Piana cloth is not inferior to a 320 GSM one. They are built for different weather.

Weight is only half the story

Two suits at the same GSM can feel completely different, because fibre and weave matter as much as weight.

• Wool is the default for good reason. It breathes, it recovers from creasing, and it regulates temperature better than any synthetic. It works from 200 GSM to 400 GSM.
• High twist wool is the underrated answer for Australian summers. The yarn is twisted more tightly, which creates tiny air gaps and makes the cloth breathe far better than its weight suggests. It also resists creasing, which linen does not. If you want summer comfort without the rumpled look, this is the cloth.
• Linen is the coolest fibre available and it will crease within an hour of putting it on. That is not a fault, it is what linen does, and for a beach or garden wedding it looks right. If crumpling will bother you, do not choose linen.
• Wool-linen blends are the compromise most people actually want. The linen brings the breathability, the wool brings the recovery. Excellent for Brisbane, Perth and northern summer weddings.
• Hopsack is an open, basketweave wool. It looks textured, breathes well and is forgiving. A good choice for a summer sports jacket.
• Flannel is a brushed wool with a soft surface. Warm, matte and beautiful in winter. Wrong above about eighteen degrees.
• Tweed is heavy, textured and hardwearing. Right for a cold-weather wedding or a winter three piece. Wrong for anything else in this country.
• Mohair blends have a subtle sheen and spring back well. Traditional for black tie, and cooler than the equivalent weight in pure wool.

Lining changes everything

This is the detail that gets ignored, and in humidity it matters more than the GSM.

• Fully lined. A complete lining through the body and sleeves. Cleanest finish, best structure, warmest. Standard for business and winter suits.
• Half lined. Lining across the shoulders and back, open through the lower body. Noticeably cooler, still tidy inside. The right default for most Australian summer suits.
• Unlined. No body lining, seams finished by hand. Coolest by a wide margin, softest, and it shows the maker's work because there is nowhere to hide. Right for linen and for the tropics.

City by city

Sydney

Humid subtropical. Warm, sticky summers and mild winters that rarely justify a heavy suit. A 250 to 300 GSM wool covers the year. For a summer wedding, drop to 240 GSM and go half lined. Sydney's humidity is the thing people underestimate. A January ceremony outdoors is closer to Brisbane conditions than to Melbourne.

Melbourne

Genuinely cold winters and famously unstable weather. A 280 to 320 GSM wool is the sensible base, and for a winter wedding flannel or tweed is worth the weight. Melbourne's four-seasons-in-a-day reputation is a real tailoring problem, and the answer is a three piece. The waistcoat lets you take the jacket off without losing the outfit.

Brisbane

Hot, humid summers and mild winters, which means most of the year is warm. Go 220 to 250 GSM, high twist wool or a wool-linen blend, half lined or unlined. A standard fully lined mid weight suit is uncomfortable here and it will show in the photographs.

Perth

Long, hot, dry summers and mild wet winters. Because the humidity is lower than the east coast, you can hold a slightly crisper cloth. High twist wool at 230 to 260 GSM performs beautifully. Linen blends work for summer weddings.

Adelaide

Mediterranean, dry heat, and summer temperatures that regularly run past the mid thirties. Similar to Perth. Lightweight to mid weight wool for most of the year, linen blends for a summer ceremony.

Canberra

The widest annual range of any Australian capital, with genuine frosts in winter and dry heat above thirty-five in summer. Canberra is the one city where a January wedding and a July wedding need different suits. Around 250 GSM for summer, 300 to 320 GSM for winter. If you are buying one suit for Canberra, buy the winter one and take the jacket off in February.

Hobart

The coolest capital. A heavier cloth earns its place here: 300 to 340 GSM wool, flannel or tweed, fully lined. Hobart is one of the few places in Australia where a proper winter-weight suit gets worn as intended.

Darwin

Tropical, with a wet season and a dry season and heat throughout. This is the hardest climate in the country to dress formally for. Linen or wool-linen at 200 to 240 GSM, unlined, and consider whether a full suit is the right call at all. A jacket and separate trouser is often the more comfortable, and more honest, answer.

Choosing for a wedding specifically

A wedding suit is worn for eight to twelve hours, much of it standing, often outdoors, frequently in photographs. That changes the maths.

• Go one step lighter than you think. Nerves and sun add heat that a fitting room never shows.
• Consider where the ceremony actually is. A vineyard in the Hunter in February and a church in Hobart in June are not the same brief, whatever the calendar says.
• Think about the whole party. Groomsmen stand in the sun for photographs longer than anyone. If you are matching a party to one cloth, weight for the person who will be least comfortable.
• Match the season, not the trend. A heavy three piece photographs beautifully and is miserable in the heat. If the wedding is in summer, a lighter cloth in the same colour will look near identical in pictures and be wearable by the reception.

More on cloth, colour and cut for the day itself in our wedding suit guide.

Three mistakes worth avoiding

• Buying to a photograph. A cloth that looked right in an overseas lookbook was probably chosen for a northern hemisphere climate. Australian conditions are different from most of the places suiting content is produced.
• Assuming heavier means better. Heavier cloth drapes well and structures well, and it is the wrong choice for most of this country most of the year.
• Ignoring the lining. People spend an hour choosing between 250 and 270 GSM and thirty seconds on the lining, when the lining will make a bigger difference to how the day feels.