What Does UPF 50+ Mean in Swimwear?

UPF 50+ is a rating used for fabrics that provide a high level of protection from ultraviolet radiation. A UPF 50 fabric allows about 1/50 of the sun's ultraviolet radiation to pass through the material, which means roughly 98% is blocked.

That makes UPF useful when evaluating swimwear, rash guards and other garments worn in strong sunlight. It does not, however, replace sunscreen on uncovered skin or tell you everything about how a garment will perform in real life.

What does UPF stand for?

UPF stands for Ultraviolet Protection Factor. It measures how effectively a fabric blocks ultraviolet radiation from reaching the skin.

The Skin Cancer Foundation explains that a UPF 50 fabric blocks about 98% of UV radiation and lets about 2% pass through. ARPANSA also classifies UPF 50 and 50+ fabrics as providing excellent protection.

What is the difference between UPF and SPF?

UPF applies to fabrics and clothing. SPF applies to sunscreen.

UPF describes how much ultraviolet radiation passes through a textile. SPF is a different testing system for topical sun-protection products. They should not be treated as interchangeable numbers.

Does UPF 50+ mean complete UV protection?

No. It means the fabric provides a very high level of UV protection, not total protection.

Coverage also matters. A bikini only protects the skin that the fabric physically covers. Uncovered areas still need appropriate sun-protection measures.

Does every swimsuit have UPF 50+?

No. Different fabrics can have different UPF performance depending on fibre type, knit or weave density, colour, stretch and other construction factors. A recycled fabric is not automatically UPF 50+ simply because it is recycled.

This is why UPF should be treated as a separate product attribute rather than assumed from the material name.

Does stretching swimwear affect sun protection?

Fabric construction and tension can affect how much light passes through a textile. In practical terms, a garment should fit as intended rather than being stretched far beyond its normal fit.

When buying swimwear, choose the size based on the product's fit guidance rather than deliberately sizing down for compression.

What does EcoAGN state about UPF?

EcoAGN's current active bikini product pages state UPF 50+ alongside recycled stretch fabric, OEKO-TEX® Standard 100 and GRS recycled-content certification claims.

You can review these attributes on individual products in Bikini Tops, Bikini Bottoms or through Build Your Bikini.

Is UPF 50+ useful for swimwear if most skin is still uncovered?

Yes, but within its limits. The fabric protects the area it covers. For a bikini, that is a smaller area than for a long-sleeved rash guard, so UPF should be understood as one layer of sun protection rather than the entire strategy.

Frequently asked questions about UPF 50+

How much UV does UPF 50 block?

A UPF 50 fabric blocks approximately 98% of ultraviolet radiation, allowing about 2% to pass through.

Is UPF 50+ better than UPF 30?

UPF 50+ provides a higher measured level of UV protection than UPF 30. Both are considered strong ratings, but 50+ is classified as excellent protection by organizations such as ARPANSA.

Does UPF replace sunscreen?

No. Fabric only protects the skin it covers. Sunscreen and other sun-protection measures remain relevant for exposed skin.

Related EcoAGN guides

Read What Is Recycled Swimwear? and How to Choose a Bikini Top and Bottom Separately.