When you go to buy sunscreen, you might look for one thing: SPF.
It stands for sun protection factor, and based on that name, it seems like it should tell you how well you'll be protected from the sun.
Except… that's not totally true.
Because while SPF might sound like a perfect, rational scientific unit, there are a lot of flaws in the way it's named and the way it's tested.
So if you want to be as protected from the sun as possible, you're going to have to know a lot more than that one number.
First, as a disclaimer, it's worth noting that countries approach sunscreen regulations differently.
This episode is a good general overview, but keep in mind that things might be different where you live.
Okay, that being said, onward.
Essentially, SPF measures how much radiation is blocked from reaching your skin.
So if it's SPF 30, it will protect you against thirty times more exposure than if you didn't wear sunscreen.
