UV Protection: What UPF Ratings Mean?
Posted by ecostinger on 6th Aug 2026
A stinger suit's sun protection is measured by its UPF rating, which tells you how much ultraviolet radiation the fabric blocks before it reaches your skin. Understanding how that number differs from sunscreen SPF, and where the fabric leaves gaps, helps you judge whether a suit is doing the job you expect.
UPF 50+ Versus SPF Ratings
UPF stands for Ultraviolet Protection Factor and applies to fabric. SPF, or Sun Protection Factor, applies to sunscreen and measures only UVB rays.
UPF accounts for both UVA and UVB radiation, which makes it the more complete measure for clothing.
A UPF 50 rating means roughly 1/50th of UV radiation passes through the material — about 2% — so approximately 98% is blocked. UPF 50+ is the highest rating commonly issued, and The Skin Cancer Foundation classifies ratings in this range as excellent.
|
UPF Rating |
UV Blocked |
Classification |
|
15–24 |
93.3–95.9% |
Good |
|
25–39 |
96.0–97.4% |
Very good |
|
40–50+ |
97.5–98%+ |
Excellent |
Most quality stinger suits are rated UPF 50+. Check the label rather than assuming coverage equals protection.