May the Force Be With You: The Force of UV Protection, That Is


Clothing with UPF is popping up all over the place, including in all Cabana Life sun protective clothing. You might know what SPF means (it stands for sun protection factor), but what the heck is UPF? And why should you care if you’re wearing clothing that has it?

What is UPF?

UPF stands for ultraviolet protection factor. In a nutshell, it’s the rating of how well fabric blocks out the sun’s harmful rays. SPF is the rating system used for skincare products that contain sunscreen. UPF is the rating system for clothing.


The SPF of a sunscreen tells you how effectively the product blocks UVB rays. Those are the sun’s ultraviolet rays that can contribute to sunburn, the most immediate and obvious sign of sun damage.

The UPF of a fabric tells you how effectively the fabric blocks UVA and UVB rays. Although UVA rays don’t make your skin turn red or blister, they can still contribute to sun damage. UVA rays can get through the clouds and glass, reaching your skin when you least expect it. UVA rays are responsible for premature aging and wrinkles. They may also cause skin cancer.

As UV rays come in contact with clothing, they are converted into heat. Heat energy can’t damage the skin the way ultraviolet energy can. Different types of clothing do a better job at absorbing UV rays vs. transmitting them toward the skin.

The UPF Rating Scale

UPF clothing was first standardized in Australia, where sun protection is a major concern. Scientists came up with a way to test fabrics in order to gauge how well they blocked UV rays and came up with a scale that was adopted by clothing companies around the world.

Clothing can have the following UPF ranges:

  • 15-24: Lets about 4-6% of UV rays through
  • 25-39: Lets about 3-4% of UV rays through
  • 40-50: Lets about 2.5% of UV rays through
  • 50+: Lets less than 2% of UV rays through

Clothing with a UPF of less than 15 cannot be promoted as being effective against UV rays.

So the next time someone asks you what is UPF when you’re talking about how much you love Cabana Life sun protective clothing, you can give them an educated response.

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