If you've ever wondered what UPF sun protective clothing actually means or how it compares to the SPF in your sunscreen, you're not alone. Both ratings measure sun protection but they work in completely different ways. Understanding the difference is one of the simplest steps you can take toward building a smarter, more effective sun safety routine this summer.
What is SPF?
SPF stands for Sun Protection Factor and it measures how well a sunscreen protects your skin from UVB rays, the rays most responsible for sunburn. An SPF 50 sunscreen blocks about 98% of UVB rays when applied correctly. The key phrase there is when applied correctly. Most people apply far less sunscreen than needed and forget to reapply every two hours, especially after swimming or sweating. Even the best sunscreen on the market can only do so much if it's not used consistently.
It's also worth noting that SPF does not measure protection against UVA rays, the rays that penetrate deeper into the skin and are strongly linked to premature aging and melanoma. Broad spectrum sunscreens cover both UVA and UVB, which is why checking that label always matters.
What is UPF?
UPF stands for Ultraviolet Protection Factor and it measures how much UV radiation, both UVA and UVB, a fabric blocks from reaching your skin. A UPF50+ rating means the fabric blocks up to 98% of the sun's harmful rays. Unlike sunscreen, UPF sun protective clothing doesn't wear off, doesn't need reapplying, and doesn't miss a spot. As long as you're wearing it, you're protected.
Not all clothing offers meaningful UV protection. A standard white cotton t-shirt provides roughly UPF 5, blocking only about 80% of UV rays. Wet fabric offers even less. Watskin's UPF sun protective clothing is engineered from premium fabric specifically designed to maintain its protective properties wash after wash, swim after swim.
Do You Still Need Sunscreen if You're Wearing UPF Sun Protective Clothing?
Yes, always. UPF sun protective clothing covers the skin beneath it but your face, neck, hands, and any exposed areas still need sunscreen. At Watskin we always recommend wearing broad spectrum SPF 30 or higher alongside your UPF50+ sunwear for complete protection. The two work together, not in place of each other.
How to Build the Smartest Sun Safety Routine
Think of UPF sun protective clothing and sunscreen as partners rather than alternatives. Start with a broad spectrum SPF 30 or higher on all exposed skin and reapply every two hours. Layer your Watskin UPF50+ pieces over the top for consistent, reliable coverage that holds up all day. Add the Sienna Hat for your face and neck and you've built a sun safety routine that's as stylish as it is effective.
The Bottom Line
SPF and UPF are both essential tools in your sun protection toolkit. SPF tells you how well your sunscreen performs against UVB rays. UPF tells you how well your UPF sun protective clothing performs against the full UV spectrum. Together they give you the most complete protection possible. Watskin exists to make the clothing side of that equation something you actually look forward to wearing every single day. Live in the Light.