What is SPF?
SPF stands for Sun Protection Factor. This is a multiplier that tells you how much longer you can remain in the sun without a burn when wearing a sunscreen. For instance, if you can usually tolerate the sun for 10 minutes without a burn, an SPF 15 will provide you with 15 times that, or 150 minutes of protection without burning. Regardless of the SPF level you use, you should reapply sunscreen every two hours or immediately after swimming or sweating to help keep your skin protected.