What Does UPF 50+ Actually Mean?
UPF 50+ is the highest sun protection rating available in Australia. Under the Australian and New Zealand standard AS/NZS 4399, a UPF 50+ garment blocks a minimum of 98% of UV radiation, letting 2% or less through the fabric.
What the number measures
UPF stands for Ultraviolet Protection Factor. It is a measure of how much UV radiation a fabric stops, tested on the fabric itself. The standard sorts garments into three bands:
- UPF 15 is classified as minimum protection, letting up to 6.7% of UV through.
- UPF 30 is classified as good protection, letting up to 3.3% through.
- UPF 50 and 50+ are classified as excellent, letting 2% or less through.
Australia does not rate anything above 50+, so that is the ceiling. A brand claiming a higher number is not working from the Australian standard.
What it does not tell you
This is where people get caught out. UPF is a rating for the fabric, not for you. Three things it does not account for:
- Coverage. A UPF 50+ garment protects the skin it covers and nothing else. A short sleeve rashie leaves forearms exposed, which is why long sleeves and a high neck matter if you are out for hours.
- Fit and stretch. Fabric stretched tight over skin has a lower effective rating than the same fabric relaxed, because the weave opens up. A rashie that is a size too small protects less than the label suggests.
- Wear and age. Chlorine, salt, sunscreen and hundreds of washes all degrade fabric over time. A rashie that has gone thin and baggy is not performing like a new one.
UPF clothing is also not a replacement for sunscreen on the bits it does not cover. Face, ears, neck, hands and feet still need looking after.
What to look for in a rashie
Beyond the rating itself: a high neck, long raglan sleeves that do not bind at the shoulder, a fabric with enough elastane to hold its shape, and a cut that is close but not stretched. Chlorine-resistant yarn is worth paying for if you swim in pools, because standard elastane gives up fast in chlorine.
What Skwosh rashies are
Our mens rashies and kids rashies carry a UPF 50+ sun rating. They are made from an 80% polyester, 20% elastane blend with Lycra Xtra Life, which is the chlorine-resistant version of the yarn, so they hold their shape through a summer of pool days rather than going slack by January. They have a high neck and raglan long sleeves, and they are designed in Australia.
Adult sizes run XS to 2XL and kids run 2 to 12, in the same navy, so you can match the little legend at the beach. They are cut to sit close without being tight, which is the fit that actually delivers the rating on the label.