SPF, sunscreen, clothing, and protection strategies.
Expert advice for sun-safe outdoor living
Browse all articles in the Sun Protection category
Master the science of SPF, learn when and how to reapply sunscreen, and understand what those numbers really mean for your protection.
Match today’s UV index to the right SPF. Complete chart covering UV 0-11+, broad-spectrum rules, reapplication timing and how much sunscreen to apply.
SPF 50 blocks about 98% of UVB rays; SPF 100 blocks about 99%. The real difference isn't the number — it's reapplication.