What do your waterproof ratings mean?Updated a year ago
Fabric ratings typically come in one format, two numbers separated by a backslash. The first number is the waterproof rating and the second is the breathability rating. The higher the number, the better the rating. Waterproof ratings are determined by how high (in millimeters) you can suspend a column of water over a section of fabric before it leaks. Breathability ratings are more abstract as it's more difficult to recreate all outisde elements but are usually based on the movement of heat and air through a fabric.