3mm vs. 5mm Wetsuit: Choose the Right Wetsuit

Surfing, swimming, or other water sports are fun until you start shivering in cold water. Only a good wetsuit can protect you from adverse consequences like hypothermia. But if the wetsuit isn’t of the right thickness, you might get cold or have restrictions in limb movement.

We will go over two popular choices, 3mm vs. 5mm wetsuit, to differentiate their features and help you choose the right wetsuit. Alongside, you will get a comparative idea of what wetsuit will be perfect for what temperature range. Without any further due, let’s get started.

What Does 3mm Wetsuit Mean?

Brands use two or three digits separated by a slash to express the thickness of wetsuits. Though we commonly know 3mm wetsuits, their actual thickness is 3/2mm, where the first digit represents the thickness of neoprene at the torso area.
The last digit denotes the thickness of the material in the arms and legs. As your arms and legs do more movement than the torso area, the thickness in those areas is less for better flexibility.
These wetsuits are perfect for moderately cold temperatures ranging from 14 to 18 degrees Celsius. 

What Does 5mm Wetsuit Mean?

5mm wetsuits are the ultimate necessity in biting cold water of 8 to 12 degrees Celsius. Is 5mm wetsuit too thick? No, they will usually have a thickness of 5/4/3mm. It means the thickness of the neoprene at the torso area will be 5mm. The thickness in the legs and arms will be 4mm and 3mm, respectively.
Due to the greater thickness, these wetsuits will keep you warm enough. The thinner arms and legs area will ensure your limb movement is unrestricted. You might need to use wetsuit accessories like boots, hoods, and gloves in this temperature range.

How Much Wetsuit Thickness Do I Need?

This will depend on the answer to several questions. You need to consider the water temperature, wind speed, sensitivity to coldness, and many more. Let’s understand them in a bit more detail.

Water Temperature

The first thing you need to focus on is the water temperature, where you will frequently use the wetsuit. Here is a chart to guide you through the relation between the thickness of the wetsuit with the water temperature.

Water Temperature

Wetsuit Thickness













Air Temperature and Speed

The ambient temperature is also important in determining the thickness of your wetsuit. If the wind speed is high and the sunlight is low, the water will feel colder. So, you might need to use a thicker wetsuit at the same water temperature. Check the 3mm vs 7mm wetsuit comparison here


Not all people are equally sensitive to coldness. If you tend to catch a cold quickly, you will need a thicker wetsuit than others. For example, where someone needs a 3mm wetsuit, you might need a 5mm wetsuit in the same water.

Activity Level

If you indulge in rigorous activity, your body will produce more heat than normal activities. In such cases, you will need a thinner wetsuit.

3mm vs 5mm Wetsuit: What Are the Key Differences?

The key difference between 3mm vs 5mm wetsuit is their thickness in different areas. Let’s explore their differences based on other factors as well.

Torso Thickness

As the neoprene of your wetsuit faces the least movement in the torso area; it is usually the thickest part of the wetsuit. 3mm wetsuits have a torso thickness of 3mm, as the name suggests. They typically have a thickness of 2mm in the arms and legs.
5mm wetsuits will have a thickness of 5mm in the torso area and 3-4mm in the arms and legs.

Zipper Position

Wetsuits commonly have two zipper positions, chest, and back. Back zip wetsuits are more convenient to wear or remove. They have a zipper along the spinal cord.
Chest zip wetsuits are a bit tricky to wear and remove. The neck cutout should fit properly so that no water can invade the suit. You can find more on chest zip or back zip wetsuit here.

Seam Type

Depending on the water temperature and use cases, you can choose from flatlock stitched, sealed, or sealed and taped wetsuits. 3mm vs 5mm wetsuit triathlon will require sealed wetsuits in temperatures more than 58℃. Sealed and taped wetsuits will be perfect for temperatures between 40℃ and 58℃.

3mm Wetsuit

5mm Wetsuit

Torso Thickness - 3mm

 Arms and Legs Thickness - 2mm

Torso Thickness - 5mm

 Arms and Legs Thickness - 4mm

Flatlock Stitched or Sealed

Sealed and Taped

Suitable for temperatures greater than 16℃

Suitable for temperatures greater than 9℃

5mm vs 3mm: Which One to Choose for Overall Comfort?

We want to leave this on your fine sense of judgment. As the necessity for protection will vary from person to person, only you can determine the right thickness of the wetsuit.
We suggest you consider all the factors we have mentioned above before choosing one.

 If you target water in normal temperatures, 3mm wetsuits will be more comfortable in terms of flexibility and warmth.

But if you are jumping into the water in cold winter months, you might need a 5mm wetsuit along with 3mm vs 5mm wetsuit boot, hood, and other accessories.


Let’s get the answer to a few frequently asked questions.

Is 5mm wetsuit too thick for swimming?

5mm wetsuits are moderately thick to keep your from cold water. The torso area is the thickest of all, but it won’t move much. Arms and legs areas are thinner, so you won’t feel any issues while swimming.

Is wetsuit material waterproof?

Wetsuits are usually made of Neoprene, a rubber compound that works as a great insulator. But neoprene isn’t waterproof like material used in dry suits. If the wetsuit doesn’t fit you snugly, you can get wet.

Is 3mm wetsuit OK for winter?

The average water temperature in winter remains close to 9℃ in the UK. So, is a 3mm wetsuit enough for that temperature? You might already know from the chart above that a 3mm wetsuit won’t be suitable at this range. Get at least a 5mm wetsuit for winter.


Before we draw the curtain, let us remind you once again that choosing the right wetsuit thickness is crucial to keep yourself warm and comfortable. The wetsuit should protect you from shivering cold and keep you comfortable enough to move your arms and legs.

Now that you know the use cases of 3mm vs 5mm wetsuit, you can easily pick the right one for your purposes. Don’t just fall for a wetsuit because it looks cool. Judge it based on its thickness in different areas, type of seams, and zippers, and choose the right wetsuit to ensure your spontaneity in the water.

Norma A Robertson

Hey, my name is Norma A Robertson. My hobbies include paddle boarding, kite surfing, snorkeling, scuba diving, etc. I started this website to share my experience and ideas as well as review products that interest me to help everyone who reads it. I hope you find what you are looking for in my articles.

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