What Is SPF?

SPF stands for Sun Protection Factor. It measures how well sunscreen will protect you from the sun’s harmful rays.

You see SPF on sunscreen bottles every summer and you know it’s important, but do you know exactly what it does and what it protects against? A common misconception is that the higher the measurement of an SPF, the stronger the protection against the sun. Unfortunately, that is not true.

The SPF number tells you how long the sun’s UV radiation will take to burn your skin. For example, an SPF of 15 means it will take 15 times longer to burn your skin than if you weren’t wearing sunscreen. A higher SPF number does not actually mean it will protect you more than a lower SPF does.

An SPF of 30 isn’t necessarily twice as strong as an SPF of 15. In fact, high SPFs provide only a small percent increase in sunburn protection. SPF 15 blocks 93% of UVB rays, SPF 30 blocks 97% of UVB rays, and SPF 50 blocks 98% of UVB rays.

SPF only protects you against UVB rays, so you still need to be careful and aware of the UVA rays. Products like our SunShade were designed specifically to protect you against UVA rays with UPF.