Wetsuit Thickness Explained
Wetsuit thickness is measured in millimetres and is typically shown as two (sometimes three) numbers. The first number refers to the thickness around your core and torso, while the second refers to the arms and legs. A 3/2 wetsuit, for example, has a 3 mm core and 2 mm limbs. The torso is thicker because it does most of the work keeping your vital organs warm, while the limbs stay thinner so you can paddle, kick, and stretch without restriction. Short-arm and short-leg suits — often called shorties — usually have a single thickness throughout.
Wetsuit Thickness Chart
Wetsuits are often grouped by season because seasons track closely with water temperature. You can also skip the season labels and just match your suit to the water temp. The chart below is a solid starting point, but it's a guideline — personal factors always play a role.
What Wetsuit Thickness Do I Need?
| Women | Men | Kids | Temp (°C) | Season |
|---|---|---|---|---|
| UV Shirt or Lycra | UV Shirt or Lycra | UV Shirt or Lycra | 26+ °C | Summer |
| 1 mm Wetsuit | 1 mm Wetsuit | 1 mm Wetsuit | 21° – 25°C | Summer |
| 2 mm or Shorty | 2 mm or Shorty | 2 mm or Shorty | 18° – 20°C | Spring / Summer |
| 3/2 mm or 4/3 mm | 3/2 mm or 4/3 mm | 3/2 mm Wetsuit | 12° – 17°C | Spring |
| 4/3 mm or 5/4 mm | 4/3 mm or 5/4 mm | 4/3 mm Wetsuit | 8° – 11°C | Fall |
| 5/4 mm or 6/5 mm | 5/4 mm or 6/5 mm | 5/4 mm or 6/5 mm | 4° – 7°C | Fall / Winter |
| 7+ mm Wetsuit | 7+ mm Wetsuit | 7+ mm Wetsuit | Below 3°C | Winter |
Wetsuit Thickness by Water Temperature
As the chart shows, wetsuit thicknesses run from 1 mm all the way up to 6 or 7 mm. Most of us live in the middle of that range. A 2 mm shorty handles water between 18° and 20°C and makes an excellent summer suit for temperate coastlines. When fall arrives and temperatures slip to 12°–17°C, a suit with a 3 mm core and 2 mm limbs (or a 4/3) takes over — the choice depends on how quickly you cool down and how active you are. A 4/3 also works well in 8°–11°C water, though many people step up to a 5/4 for extra warmth in those conditions. For genuinely cold winter water, a hooded 5/4 is essential, paired with gloves and boots to protect your hands and feet from the bite.
Other Factors Worth Considering
Water temperature is the headline, but it's not the whole story. Wind chill and the activity you're doing matter too. The more time your body spends above the water — and the more skin exposed to air — the more wind and air temperature will drain your body heat. Swimmers and bodyboarders are submerged most of the time, while windsurfers, kitesurfers, and paddleboarders are mostly above the water. That means a surfer often wants a thicker suit than a windsurfer in the same cold water, and might opt for something thinner when the water is warm but the air is cool. Your personal metabolism, body composition, and how long your session runs all factor in as well.
Built for Cold-Water Adventures
When the water turns serious, you need a suit that's serious too. Engineered for full coverage, superior warmth, and unrestricted mobility — this is the wetsuit that keeps your season going when the thermometer drops.
Shop the Zeagle Bare 5mmGuidelines are a great starting point, but your own comfort is the real test. Build a wetsuit quiver that covers your conditions and you'll be on the water all year long.