What Is UPF? How It Differs From SPF, and Choosing UV-Protective Wear

Sunlight is both a source of energy for outdoor trips and something that quietly damages the skin if exposed to it for too long. When it comes to sun protection, most people immediately think of sunscreen. However, along with the development of textile technology, many sportswear items today also integrate UV skin protection through the UPF rating. So what is UPF, how does it work, and how do you choose the right sun-protective clothing? Let's find out with Supersports in the article below.

What Is UPF Rating? Distinguishing It From SPF In Sunscreen

UPF (Ultraviolet Protection Factor) is a rating that measures a fabric's ability to protect skin from ultraviolet rays (UVA and UVB). The higher the UPF rating, the less UV radiation passes through the fabric. A UPF 50 shirt allows only about 1/50, meaning 2%, of UV rays through to the skin.

Although both are sun-protection ratings, UPF and SPF are not the same. SPF is the rating used for sunscreen, mainly assessing the ability to protect skin from UVB rays. UPF, on the other hand, is the rating used for clothing, assessing a fabric's ability to block both UVA and UVB rays. Because they apply to two different types of products, these two ratings cannot be directly converted between one another.

UPF Rating Classification By UV Protection Ability

According to international standards, fabric is classified into four levels:

• Below UPF 15: not considered to have significant sun-protection ability
• UPF 15-24: good protection, can block about 93.3–95.9% of UV rays, suitable for short outdoor activities or when sun intensity isn't too harsh.
• UPF 25-39: very good protection, blocking 96–97.4% of UV rays, suitable for activities like running, hiking, or camping with longer sun exposure.
• UPF 40-50+: excellent protection, blocking 97.5% of UV rays or more, the level recommended for extended outdoor activities.

The Skin Cancer Foundation grants its Seal of Recommendation to products with a minimum UPF of 30, and considers UPF 50+ the ideal level. One detail few people know: "50+" isn't the fabric's actual limit, but the highest number allowed to be printed on the label under the ASTM D6603 standard. Even when a fabric measures much higher in the lab — some premium technical fabrics reach over UPF 100 — the product label can still only state a maximum of "50+", not a specific higher number.

How Does UV-Protective Clothing Work?

Unlike sunscreen, which forms a film on the skin's surface, UPF clothing blocks UV rays right at the fabric layer. When sunlight hits the fabric, part of the UV rays is reflected, part is absorbed by the fibers and dye, and only the remainder passes through the gaps between fibers to reach the skin. The higher the UPF rating, the less UV radiation passes through the fabric.

To achieve a high UPF rating while still ensuring comfort when worn, manufacturers usually optimize several factors during fabric development, including:

• Weave structure: The tighter the weave, the smaller the gaps between fibers, and the harder it is for UV rays to pass through.
• Fiber type and treatment technology: Polyester, nylon, or UV-protection technologies built into the fibers usually deliver higher effectiveness than many ordinary fabrics.
• Color and dye: Darker dyes can absorb more UV rays, contributing to increased protection.

Things To Note When Choosing Sun-Protective Clothing

Material is the fundamental factor, more important than how thick or thin the fabric feels when handled:

• Cotton, linen: lowest UPF, only 5-10, even though they may look thick
• Polyester: UPF 12-77 depending on the weave, thanks to a molecular structure that naturally absorbs UV — most common in sportswear and outdoor gear
• Parachute fabric: woven almost completely tight, UPF can exceed 45, but it's stuffy and poorly breathable
• Denim, khaki: good sun protection thanks to a dense weave, but heavy and heat-retaining

Color also has an effect, though it's no longer an absolute deciding factor. Dark colors absorb UV better than light colors, but they also absorb more heat — not because more UV passes through, but because heat is retained in the fabric. Many technical fabrics today use titanium dioxide or optical brighteners woven directly into the fabric, allowing even light colors to reach UPF 50+ on par with dark colors.

Coverage: long sleeves, a high collar, and a shirt length sufficient to limit the area of skin directly exposed to UV rays. No matter how high the UPF, it's meaningless for skin that isn't covered.

Notable Sports Brands With UV-Protection Technology

With nearly 90 years of development in the outdoor field, Columbia is one of the pioneering brands in sun-protective clothing. Many of the brand's product lines apply Omni-Shade™ technology, which helps limit UVA and UVB rays passing through the fabric, and have been awarded the Seal of Recommendation by The Skin Cancer Foundation for meeting standards on UV skin protection. In addition, Columbia also applies moisture-wicking and cooling technologies, bringing comfort during outdoor activity.

Besides brands specializing in outdoor gear, many sports brands also equip UV protection on certain running and outdoor training apparel lines. However, instead of developing a proprietary sun-protection technology, these brands usually integrate a UPF rating into each product, combined with heat- and sweat-management technologies to increase comfort during activity.

• Under Armour is known for its high-performance apparel for running and training, with many running, golf, and outdoor shirt lines reaching UPF 50, combined with Iso-Chill to increase comfort during activity.
• Originating from running and with decades of development in this field, Nike has also developed many running apparel lines that reach UPF 40+, combined with Dri-FIT technology that helps control sweat and maintain a dry, breathable feel in hot weather.
• With more than 75 years of experience developing sportswear, adidas has developed many running and golf shirt lines reaching UPF 50+, while also applying AEROREADY to increase comfort during outdoor activity.

Frequently Asked Questions

1 - Does UPF Clothing Feel Hot And Stuffy?

UPF fabric itself doesn't have a cooling or moisture-wicking function, but most brands today combine UPF with their own sweat- and temperature-management technology, so it isn't hotter than regular clothing if you choose the right product line.

2 - How Long Does The UV Protection Of UPF Clothing Last?

Because the sun-protection ability lies in the fiber structure and weave, not in an outer coating, this effectiveness usually lasts the entire lifespan of the product, and doesn't fade or disappear with the number of washes as many people worry.

3 - Do You Still Need Sunscreen When Wearing UPF-Rated Clothing?

Yes. UPF clothing only protects the areas of skin it covers. Exposed areas such as the face, hands, and feet still need their own sunscreen.

4 - Is UV-Protective Clothing Effective In Water?

Yes, and it's even more effective than sunscreen in this case because it doesn't wash off in water, making it suitable for activities like swimming, boating, and fishing. This is also a more environmentally friendly choice, since some ingredients in sunscreen can affect underwater ecosystems.

5 - Do You Need To Wear UV-Protective Clothing In Winter Or On Overcast Days?

Yes. UV rays exist year-round, even on cloudy or cold days — clouds only block a small portion of UV rays, not all of it. During extended outdoor activities like hiking or running in winter, skin is still exposed to UV without many people realizing it.

6 - Do Children Need To Wear UV-Protective Clothing?

Children's skin is thinner and more sensitive than adults', and more prone to UV damage, so UPF clothing is usually recommended as a priority for children during outdoor activities, especially water activities where sunscreen easily washes off.

Buy Authentic UPF Clothing At Supersports

To ensure the UV protection matches the manufacturer's stated claims, you should choose products from reputable retailers. At Supersports, you can easily find many lines of UPF-rated sun-protective clothing from the world's leading sports brands, suitable for running, hiking, golf, and many other outdoor activities.

Supersports is VIETNAM'S NO.1 AUTHENTIC SPORTS FOOTWEAR, APPAREL AND ACCESSORIES RETAILER AND DISTRIBUTOR. The brand is part of Central Retail Group - a leading retailer from Thailand.

Supersports owns a retail network with more than 30 well-known sports brands such as: Nike, Adidas, Crocs, Puma ...Among these, Supersports is the official and exclusive distributor of the brands: Under Armour, HOKA and Columbia. We are committed to bringing authentic, top-quality products to sports enthusiasts in Vietnam.