On October 18, 2023

Waterproof & Breathability Ratings Explained.

For some people this is an important thing to know when purchasing their technical outerwear. For others, they wouldn’t even know what it means and frankly don’t really care. Which one of these you are, will largely depend on what sort of activities you are purchasing your gear for.

The below should help clarify what sort of minimum ratings you should be looking for from your products, depending on what you are planning to do in them.

What is a Waterproof Rating?

A waterproof rating is a number given to a fabric that indicates how waterproof that fabric actually is. In technical terms what force it would take for water to penetrate the fabric.

What is a Breathability Rating?

A breathability rating is a number given to a fabric that indicates how breathable it is. In technical terms how well it allows sweat to escape from the inside of the fabric to the outside.

Simply speaking - the higher the number is, the more waterproof and/or breathable the fabric is.

Waterproof Ratings:

5,000mm: Minimum rating for a fabric to be called rainproof, however not appropriate for use beyond light rain.
10,000mm - 15,000mm: A fabric in this range will withstand most downpours as well as heavy snow.
20,000 and above: This is the rating you should look for if you plan to be out in extreme conditions.

Breathability Ratings:

5,000 - 10,000g/m²: This level of breathability is fine for resort skiing, urban travel or camping in the rain, but will get a bit clammy during high-intensity activity..
10,000 - 15,000g/m²: Products in this range are suited to more adventurous activity or backcountry skiing, but extreme use and trekking uphill may prove too much.
15,000 - 20,000g/m²: An extended trip to the mountain, trekking in warm climates or otherwise working hard and perspiring heavily will require a fabric this breathable.

For example, if you are mainly skiing on piste and in fairly dry conditions, you can get away with a lower waterproof/breathability rating. However, if you are a backcountry skier in deep powder, you are going to need a higher waterproof rating so you don’t get wet from the snow as well as more breathability so you’re not dripping in sweat.

Generally speaking if you’re not doing anything too vigorous in nice weather, then you should be ok with only 5,000/5,000 waterproof/breathability in your ski jackets and trousers. If you’re spending longer days on the mountains in more of a variety of weather conditions, then you’ll probably be better off above 5,000 and more towards 10,000 in your ratings. And if you are a more adventurous skier or snowboarder who maybe prefers off piste and backcountry skiing, then you definitely want to be looking above 10,000 and closer to or even above 20,000.

The bottom line is, the higher you go the more protected and comfortable you will be in all conditions. But the most important thing is to make sure you have the very minimum waterproof and breathability rating, so you never get caught out on the mountain.

The waterproof (mm) and breathability (g/m²) ratings for all of our one piece snow suits are listed below. You will also find this information on each individual product page so you can check there as well: