What Does UPF 50 Mean?

Rayward Apparel

UPF stands for Ultraviolet Protection Factor - it’s the standard used to measure the amount of UV protection a fabric provides. The higher the UPF factor the better. UPF 50 is the highest possible rating for sun protective clothing, but what does it really mean?

Blocks 98% of all UV rays

The number 50 represents the factor to which the clothing protects the skin. When something is labeled as UPF 50 clothing, that means it provides excellent protection against harmful UV rays. For instance, a UPF 50 product allows only 1/50th of the harmful rays to penetrate the fabric. 

Sunscreen vs UPF 50

The sun emits two types of damaging UV rays - long wave ultraviolet A (UVA) and short wave ultraviolet B (UVB). It’s important to protect your skin from both. One of the key differences between UPF and SPF is that all sun protective fabrics (UPF) protect your skin from both types of radiation. Sunscreen (SPF) on the other hand only shows it’s effectiveness in protecting your skin from UVB rays. Always make sure your buying “broad-spectrum” sunscreen which protects you from both. 

We often get asked if sun protective clothing is a better option than sunscreen. Our answer - yes and no. You can’t really have one without the other. UPF 50 clothing does not ever require re-application is an excellent way to ensure you are protected from the sun, but it only protects the covered areas of your skin. In addition, even with the best apparel it’s important you also have a high quality sunscreen. Clothing can only cover so much, you still need to protect your face, neck, and other areas that are exposed to the sun.

‘Excellent’ Protection According to Standard Testing

All fabrics that list a UPF value must be tested according to the ASTM standards. The test measures UV penetration of a fabric and determines its exact UPF value, but sometimes this value is not always listed. Along with a UPF rating, the test results show the official Protection Category the fabric falls into. UPF 50 clothing falls into the ‘Excellent’ protection category, the best possible category. Fabrics with a UPF rating of 25 - 39 have ‘Very Good’ protection, and fabrics with a UPF rating of 15 - 25 have ‘Good’ protection. Anything less than UPF 15 is not considered a protective fabric. In summary, if you're going to be out in the sun, make sure you are protected with UPF 30 or better.

How Do I Know The UPF Value Of My Clothing?

All fabrics have some UPF rating, but it’s close to impossible to determine without proper testing. If a product has been tested and is designed for sun protection look for its UPF rating. First, just look on the tag and see if it's listed there. If not, you might be able to find it through a quick Google search. If it's not listed anywhere on the product or in the product details, it's likely never been tested. With any Rayward Apparel clothing, you can have the peace of mind knowing ALL of our products achieve a UPF rating of 30 or more. This is consistent with the recommendations of the Skin Cancer Foundation.

Side by side, UPF 50 clothing may look and feel the same as all of the other options, but don’t be fooled. A common misconception is that any t-shirt will keep you properly protected from the sun, which is far from the truth. The average t-shirt has a UPF value of 1-4, providing minimal protection from UV rays. UPF clothing does work and is a ‘must-have’ for anyone that loves the outdoors. In the short video below, a dermatologist from the Mayo Clinic provides some more insight: