Face Sunscreen 101: What is SPF, How Much to Use & Tips for Applying
Wearing sunscreen every single day is one of the best skin care moves you can make. Not only does daily application help prevent signs of premature aging caused by sun damage—including fine lines, wrinkles and discoloration—it also greatly reduces your chance of developing skin cancer.
For those reasons, any board-certified dermatologist you talk to will agree that wearing sunscreen is a non-negotiable part of your skincare regimen.
Keep reading for the full rundown on what SPF is, how much sunscreen to use on your face, where this step falls in your skin care routine and how often you should reapply. We're also exploring types of sunscreen, including physical and chemical sunscreens, sprays, sticks and lotions.
What Is SPF and What Does it Mean?
The term SPF stands for "sun protection factor," and refers to how long the sun's UV rays take to burn your skin once the product's been applied versus how long you'd burn without wearing sunscreen. So, if you're wearing an SPF 15 that means it would take 15 times as long to get a sunburn. Or if you're wearing SPF 30, that means it would take 30 times as long to get a sunburn.
Even though most modern sunscreens offer broad spectrum protection—which means they shield against both UVA and UVB rays—the SPF rating only refers to protection against UVB rays. The newly developed PA+ rating system refers to your level of protection against UVA rays.
Which SPF Level is Best?
A quick browse through the shelves of any skin care or cosmetics store will reveal products offering a wide range of SPF levels. It can be overwhelming to choose what SPF is best for your needs. Consider the following to determine the SPF level you should be wearing:
- SPF 15: If you're not planning to be outside much and anticipate low sun exposure, a moisturizer or makeup with a built-in base of SPF 15 can be sufficient for your everyday needs. It will protect your skin against 93 percent of UVB rays.
- SPF 30: This will protect against 97 percent of UVB rays and is recommended by the American Academy of Dermatology for adults of all ages and skin colors, and for all children over six months, especially during outdoor activities.
- SPF 50: Choose this for protection from 98 percent of UVB rays. It can be a good choice for people with a history—or higher risk—of skin cancer or if you are very fair-skinned.
- SPF 100: A triple-digit SPF factor will protect skin from 99 percent of UVB rays.
No matter the SPF rating, though, you'll need to reapply with the same frequency. (More on that in a second.)
Pro Tip: It's also encouraged to use a lip product that contains SPF 30 or higher every day.
How Much Sunscreen Should You Use on Your Face?
Knowing how much SPF sunscreen to use on your face is a key step in the quest to protect your skin from sun exposure. Unfortunately, most people don’t apply nearly as much—sometimes it's only 25 to 50 percent of what they should be wearing.
To adequately cover the surface area of your face and neck, aim for about a half teaspoon or the size of a blueberry. For the rest of your body, the rule of thumb is to use about one ounce, or the amount of a shot glass. It might feel like a lot of sunscreen at first, but this ensures you completely cover your skin.
Do You Need to Wear Sunscreen Inside?
Yes, you should wear sunscreen even when you're not in direct sunlight. That includes when you're inside, sitting in a car or even under a sun umbrella. The sun's UV rays can penetrate all these places. Sunscreen can also help protect your skin from blue light exposure, which is emitted through laptops and cell phones.
How to Apply Sunscreen on Your Face
Think of sunscreen as the (essential) cherry on top of your skin care regimen. After cleansing, toning and moisturizing, wait a few minutes for your skin care products to absorb. Then apply your sunscreen.
Remember, aim for a blueberry-size amount when applying to your face and neck, and don't forget hidden areas like your ears, lips and scalp. Massage the product onto your skin well so that it's even and smooth. If you wear makeup, then you can apply your foundation after your sunscreen has set for a couple of minutes.
It's best to apply your sunscreen 15 minutes before direct exposure. This gives the product time to absorb and begin protection.
When to Reapply Sunscreen to Your Face
Reapplication throughout the day is super important. As for how often you should apply sunscreen on your face, the consensus is to aim for every two hours when outdoors and every four hours when inside. You should also reapply frequently when swimming or sweating—ideally every time you come out of the water or wipe off.
Types of Sunscreens
If you've ever shied away from using facial sunscreen because you didn't like how it felt, we hear you. Fortunately, sunscreen formulations have changed quite a bit in even the last five to ten years. Today, there is a bevy of great formulations that make wearing sunscreen feel like less of a chore and more of a treat.
There are three primary categories of sunscreen to choose from:
- Mineral sunscreens (physical): The active ingredients in this type of sunscreen are titanium dioxide and zinc oxide, which work to block the sun's rays. They're often recommended for those with sensitive skin.
- Chemical sunscreens: These work by absorbing the sun's rays and releasing them. These are less likely to leave a white cast.
- Hybrid sunscreens: These contain both chemical and mineral active ingredients to shield you from the sun's rays.
Whether it's mineral or chemical, always make sure you're using a broad spectrum sunscreen. This means it protects against both UVA and UVB rays. UVA rays are responsible for deeper damage, including signs of aging and skin cancer, while UVB rays cause more surface-level damage, including sunburns. It's important to protect against both.
Within these three categories, you'll find different types of formulations:
- Lotions and creams: These are applied just like a moisturizer or body lotion and tend to have a creamy, hydrating feel.
- Spray sunscreen: This type is sprayed onto the skin, which makes it a popular option for hard-to-reach areas. Proper application is crucial—make sure to spray it within a few inches of your skin in a non-windy area, and then thoroughly rub it in. As an alternative, you can spray the product onto your hands and then apply.
- Stick sunscreens: Sticks are an excellent choice for smaller areas that need lots of protection, like your nose, cheeks and scalp.
- Powder sunscreens: Powder sunscreens are ideal for on-the-go touch-ups. They're compact and easy to reapply over liquid sunscreen and even makeup.
Ultimately, the best sunscreen out there is the one you reach for every day. And now that you know how much sunscreen to use on your face—and how often to reapply—you'll have no shortage of opportunities to use the product you love.