What Is SPF and Which Sunscreen Should I Use?

Before heading out for a BBQ, a day at the beach, or afternoon by the pool, don’t forget to apply sunscreen to protect your skin from the sun's harmful ultraviolet rays.

You’ve probably seen them displayed in your local store: sunscreens with SPF 15, SPF 30 — even SPF 50. How do you know which one you need? Let’s start with the basics: Sunscreen 101.

What’s is SPF?

The three-letter acronym stands for sun protection factor. It lets you know the amount of time it will take the sun's UV rays to turn your skin red after you properly apply sunscreen. Coated in sunscreen, your skin is protected from the sun’s burning rays for a period of time. For example, if you slather on sunscreen with SPF 15 it will take you 15 times longer to burn than if you didn't use sunscreen.

In general, sunscreen with higher SPF (SPF 30 and SPF 50) offers more protection against sunburn, UV and DNA damage than products with lower SPF values.

What type of sunscreen should I use?

When you buy sunscreen, look for one with broad spectrum coverage so you are protected from the sun's UVA and UVB rays.
If you're indoors most of the day, you can use a sunscreen or cosmetics with an SPF of 15 or higher. If you spend a lot of time outdoors, especially when and where the sun is strongest, choose a water-resistant sunscreen SPF 30 or higher.

Steer clear of these sunscreen myths.

Myth 1: I have dark skin so I don't need sunscreen.
False. Even though darker skin tones may not show the classic red coloring of sunburn, the sun’s UV rays will still damage unprotected skin.

Myth 2: Sunscreen with SPF 50 protection lasts all day.
False. To protect your skin, it’s important to apply two tablespoons of sunscreen every two hours and after swimming or sweating.

What do I do if I get sunburned?

If you do get a sunburn, there's not much you can do to limit the damage to your skin. There are ways to reduce pain and discomfort, though. Use aloe gel or lotion to soothe the skin. Take a pain reliever, or apply a cold, damp towel to the painful area.

Even though most sunburns heal on their own, talk to your doctor if the burn is severe. Check out this list of ways to treat a sunburn. 

Sources: How to Treat Sunburn,  American Academy of Dermatology Association, 2024; All About Sunscreen,  Skin Cancer Foundation, 2024; Tips to Stay Safe in the Sun: From Sunscreen to Sunglasses,  U.S. Food and Drug Administration, 2024; Sunburn,  Mayo Clinic, 2024