Here's What You Really Need To Know About SPF 50

I'm not going to lie, picking out a sunscreen is pretty confusing. What the heck does SPF even mean, anyway? And do the numbers really matter? Does SPF over 50 really work?!

As it turns out, sunscreen math is confusing (even to people with pHDs, dermatologist Dr. Ellen Marmur reassured me). First thing's first: What does SPF stand for? SPF stands for sun protection factor (mind blown, btw). According to Dr. Marmur, the number on the label tells you how many times longer you can be in UVB light before you'll start to burn. So, for example, SPF 15 means that you can be in the sun 15 times longer with sunscreen on than you could be without it before getting a sunburn.

So do high SPF numbers really matter? "It is unlikely that SPF 100 is better than SPF 50," says Dr. Marmur, which makes sense considering it's fairly unlikely that the sunscreen will last long enough on your skin to offer "50 Times" the protection the way the SPF number implies. "SPF 30 to 50 is the sweet spot for sunscreens in any setting. This provides you with good coverage to prevent sunburns. Look for labels that say UVA/UVB broad spectrum protection because this means you are covered for the tanning ray damage from UVA plus the burning damage from UVB. Both UVA and UVB cause DNA mutations and can lead to skin cancers."

And when it comes to sunscreen, the most important thing isn't actually the most important factor in protecting your skin — it's your own diligence. "We forget to reapply every one to two hours. We don't apply enough sunscreen. We forget to protect our backs or shoulders or legs or feet," says Dr. Marmur. "My advice? Be generous with yourself with sunscreen. Buy extra, use more, apply often."

With that in mind, here are three sunscreens in that SPF 30 to 50 sweet spot to lather your skin with all year long.

1. EltaMD

UV Daily Broad-Spectrum SPF 40, $26.50,

Not only is this sunscreen dermatologist approved, but Gigi Hadid swears by it. Considering she basically has the skin of a glowing, heaven-sent angel (seriously — I've seen it IRL), I'd say it's pretty legit.

2. TiZO 3

TiZO 3 Facial Mineral Sunscreen SPF 40, $29.99,

This is my (and Kylie Jenner's) go to daily SPF moisturizer. It comes in a tinted and un-tinted option, and goes on whipped and creamy instead of greasy.

3. Blue Lizard

Blue Lizard Australian Sensitive Sunscreen SPF 30, $12.99,

Don't be fooled by the cute name or the weird lizard cartoon on the bottle — this sunscreen is serious business. I've personally spoken to a number of dermatologists who say it's their #1 go to for themselves and their patients. It's a physical sunscreen that contains zinc oxide, and is specially formulated not to irritate sensitive skin.