What is UPF?

What is UPF?

UPF refers to Ultraviolet Protection Factor and was created as a growing concern for sun protective clothing evolved. We use this term often on our site as hats have increasingly become incorporated with fabrics and weaves that produce this sun protection quality. The factors affecting the actual protection of the fabric are calculated by the weave, color, weight, stretch and wetness of the material. Additionally in order to achieve ultraviolet protection, fabrics are sometimes treated first with a protection material and then it is up to the other factors to determine the actual UPF rating.

What do UPF ratings mean?

The UPF ratings that are claimed on this site and used as tags for clothing have been developed by the American Society for Testing and Materials or (ASTM) and are considered to be the industry standard in rating sun protective clothing. The ratings are as follows:

UPF Rating Protection Coverage % of UV Radiation Blocked
UPF 15-24 Good 93.3-95.9
UPF 25-39 Very Good 96.0-97.4
UPF 40-50+ Excellent 97.5-99+