How To Choose Waterproof Ratings for Clothing

How To Choose Waterproof Ratings for Clothing

Whether you’ve just bought a new jacket, pants, vest or even backpack, you want a clear picture of how much moisture your new gear can withstand. Waterproof rating scales help you understand how water-resistant your items are and how to care for them. In this article, we’ll go over the different types of waterproof levels and how to choose the right rating to meet your needs.

Understanding Water Resistance

waterproof vs water resistant

Water resistance is not the same thing as waterproof. Waterproof means your gear creates a barrier between you and any moisture on the surface of your garment – but water resistance simply gauges a garment’s ability to repel water from its surface. Tightly woven materials such as polyester and nylon can provide more resistance than breathable cotton but they won’t keep water out entirely.

While your gear might be water-resistant, that doesn’t mean it is waterproof. When it comes to your clothing, look for high millimeter ratings or for materials like GORE-TEX®, which provide a strong moisture barrier.

Understanding Waterproof Ratings

Not all types of “waterproofness” are the same. In addition to being waterproof, your gear might be able to withstand other elements or be totally submersible. Waterproof ratings are designed to give you all of the information you need to determine what your gear is capable of.

waterproof vs water resistance

Factors That Affect Waterproof Ratings

  • Material: When buying outdoor clothing, the fabric's ability to remain waterproof will be noted in millimeters. The higher the rating, the better that garment’s ability to keep you dry. Fabric technology like GORE-TEX® provides both breathability and waterproof features.
  • Construction: Waterproof clothing often features a construction that aids its ability to keep moisture out. Durable zippers help ensure the gear maintains its seal and won’t bend or chip. Waterproof gear often features heat-treated seams that seal the stitching. Waterproof fabrics are often treated with a coating that will cause water to bead or wick away.
  • Environment: Waterproof rating scales indicate how much water a garment can withstand, but environmental factors also affect that rating. Submersion pressure – particularly at significant depths – can cause most water-resistant items to let in moisture.
  • Duration: While water-resistant items can withstand moisture with regular use, the longer they remain exposed to water, the more their water-resistant features are tested. Items that are resistant might only handle some splashing, while others can withstand constant rain or snow.
  • Care and maintenance: Proper care for your items helps to maintain their ability to withstand water. Washing your waterproof jacket according to the item’s care instructions can help its coating and seams last longer.

What’s a good waterproof rating?

No matter which waterproof rating scale your item uses, a higher number is generally better. Water resistance and waterproofing in clothing is typically noted with a ‘k’, explained in the following section. The most common waterproof rating for outerwear is 5k – 20k, however, the right rating for you really depends on how you intend to use your outerwear.


how does waterproofing work

Fabric Waterproof Ratings

Waterproof ratings for clothing are most commonly noted with a number followed by the letter k (representing millimeters) – this number is based on the amount of water pressure the fabric can withstand before it starts to leak. For example, a 10k rating means that the fabric membrane can withstand 10,000 millimeters of water over a 1-inch area before it starts to leak. A general guideline for the levels can be found below.

Rating Explanation Good For
0 Not waterproof and will not keep you dry Dry weather
1K Repels rain but is not rainproof Sprinkling or fog
>5k Rainproof but not under pressure Light rain or snow
5K – 20k Dependable waterproofing Average rain or snow, the most common amount of waterproofing
20K+ Excellent waterproofing under increased pressures Heavy rain or snow
waterproof fabric

Tips for Keeping Waterproof Clothing in Good Condition

You can extend your gear’s ability to stay waterproof with some TLC. Following the manufacturer’s washing instructions ensures you are giving your gear the best possible care. Washing your waterproof articles on a cool water setting helps prevent damage to seams, zippers, and coatings that are designed to keep you dry. After washing, tumble drying on a low heat reactivates the DWR treatment on technical waterproof pieces. Careful storage – hanging whenever possible, laying flat, avoiding prolonged folding – helps keep the structure of the garment in its best condition. 

Waterproof ratings are designed to give you the information you need to choose the right gear for your next adventure. Consider the daily use of your gear and the context for each rating type to help you understand if a water-resistant fabric will be enough or if you need it to be waterproof.