{"id":8666,"date":"2025-11-25T12:30:00","date_gmt":"2025-11-25T11:30:00","guid":{"rendered":"https:\/\/www.flipsoc.de\/?p=8666"},"modified":"2026-10-04T14:12:57","modified_gmt":"2026-10-04T12:12:57","slug":"wetsuit-thickness-water-temperature","status":"publish","type":"post","link":"https:\/\/www.flipsoc.de\/en\/wetsuit-thickness-water-temperature\/","title":{"rendered":"Wetsuit Thickness: Which Wetsuit for Which Water Temperature?"},"content":{"rendered":"

The right wetsuit thickness decides whether you’re still smiling after an hour in the water or standing on the shore with blue lips. At the same time, you want to be able to move without fighting your suit. Too thin means freezing, too thick means stiff \u2013 and hard to put on.<\/p>\n

On labels and in shops you’ll come across figures like 3\/2, 4\/3 or 5\/4. To beginners it sounds like a secret code, but there’s a simple logic behind it.<\/p>\n

In this guide we explain the numbers, give you a table by water temperature for surfing, swimming and diving, and show why thicker wetsuits require more technique when putting them on.<\/p>\n

In short:<\/strong> The right wetsuit thickness depends on the water temperature: at approx. 18\u201323 \u00b0C a shorty or 3\/2 mm is enough, at approx. 15\u201318 \u00b0C a 3\/2 full suit, at approx. 12\u201315 \u00b0C a 4\/3, at approx. 9\u201312 \u00b0C a 5\/4 with accessories. The first number stands for the torso, the second for arms and legs. Divers usually need thicker suits at the same temperature.<\/p><\/div>\n

What do the numbers 3\/2, 4\/3 and 5\/4 mean?<\/h2>\n

The numbers give the neoprene thickness in millimetres: the first number stands for the torso, the second for arms and legs. A 4\/3 wetsuit therefore has 4 mm on the upper body and 3 mm on the limbs.<\/p>\n

The reason for this split is logical. The torso houses the vital organs, so as much warmth as possible should stay there. Arms and legs, on the other hand, have to move a lot \u2013 when paddling, doing front crawl or finning. Thinner neoprene in these areas means more flexibility.<\/p>\n

Some suits carry three numbers, such as 6\/5\/4. In that case: first number torso, second legs, third arms. Suits like these are built for very cold water and are mainly used for winter surfing or diving in cold waters.<\/p>\n

Which wetsuit thickness suits which water temperature?<\/h2>\n

The colder the water, the thicker the wetsuit \u2013 the following table serves as a rule of thumb. These are guideline values, because manufacturers vary and everyone feels the cold differently.<\/p>\n\n\n
Water temperature<\/th>Recommended thickness<\/th>Suit type<\/th>Accessories<\/th><\/tr><\/thead>\n
above approx. 24 \u00b0C<\/td>usually no wetsuit<\/td>Lycra or UV shirt<\/td>\u2013<\/td><\/tr>\n
approx. 18\u201323 \u00b0C<\/td>2 mm or 3\/2 mm<\/td>Shorty, spring suit<\/td>\u2013<\/td><\/tr>\n
approx. 15\u201318 \u00b0C<\/td>3\/2 mm<\/td>Full suit<\/td>optional<\/td><\/tr>\n
approx. 12\u201315 \u00b0C<\/td>4\/3 mm<\/td>Full suit<\/td>boots if needed<\/td><\/tr>\n
approx. 9\u201312 \u00b0C<\/td>5\/4 or 5\/3 mm<\/td>Full suit<\/td>Boots, gloves, hood<\/td><\/tr>\n
below approx. 9 \u00b0C<\/td>6\/5\/4 mm<\/td>Full suit, often with hood<\/td>Full accessories<\/td><\/tr>\n<\/tbody>\n<\/table>\n

Besides water temperature, other factors play a role: air temperature, wind, sun, your activity in the water and how long you stay in. If you get cold easily or plan long sessions, go for the next thicker option if in doubt.<\/p>\n

Surfing, swimming, diving: why does the thickness differ by sport?<\/h2>\n

The right thickness depends not only on the water but also on how much you move and how deep you go. If you’re very active, you produce heat; if you float calmly in the water, you cool down faster.<\/p>\n

Surfing<\/h3>\n

Surfers paddle a lot but also sit on the board for long periods waiting for waves. Add to that wind on wet skin. For most European spots in spring and autumn, a 4\/3 is the typical all-rounder, and a 3\/2 in summer. If you want to surf in winter, you’ll need a 5\/4 or more plus accessories. You can read more about this in our article on winter surfing<\/a>.<\/p>\n

Swimming and triathlon<\/h3>\n

Swimming and triathlon wetsuits are optimised for freedom of movement and buoyancy. According to the German Triathlon Union (DTU), they may be no more than 5 mm thick in competition. Typical suits have thicker neoprene on the torso and legs for buoyancy and very thin, flexible material at the shoulders.<\/p>\n

Because swimmers are constantly moving, less thickness than for surfing is often enough. For very cold water there are special accessories such as neoprene swim caps. You can find out what swimming in a wetsuit feels like and what to look out for in our guide to swimming in a wetsuit<\/a>.<\/p>\n

Diving<\/h3>\n

At the same temperature, divers usually need thicker suits than surfers. There are two reasons: when diving you move comparatively little, and the neoprene is compressed by the water pressure as the depth increases. A 5 mm suit therefore insulates less at depth than at the surface.<\/p>\n

That’s why 5 mm and 7 mm diving suits are common, often combined with booties, gloves and a hood. In cold lakes, semi-dry or drysuits also come into play. You’ll find the basics in the article Diving in a wetsuit<\/a>.<\/p>\n

Which is better: too thick or too thin?<\/h2>\n

If in doubt, slightly too thick is the safer choice than too thin, as long as you can still move enough. If you’re cold, you lose strength and concentration, and hypothermia is a real safety risk.<\/p>\n

Still, too thick has its drawbacks: the suit becomes stiffer, you tire more quickly when paddling or swimming front crawl, and it can get too warm in summer. That’s why many water sports enthusiasts own two suits \u2013 one for summer and one for the shoulder seasons.<\/p>\n