SPF Vs Sunscreen: What's The Difference?

With the summer sun heating up, it's getting increasingly important to protect your skin from the sun. But have you ever been confused by all the science and skincare expectations thrown at you once spring blooms and summer arrives? What's the difference between mineral sunscreen and chemical sunscreen? Do you need to use sunscreen on your hands? How can you get sunscreen into your routine?

You may see a number labeled SPF on a sunscreen container and wonder: What's the difference? Are SPF and sunscreen the same thing? Why does SPF matter when choosing the right sunscreen? If you're ignoring SPF, you might be using the wrong sunscreen and putting yourself at risk for sunburns and other damage. Put simply, SPF is a measurement, not an actual product (like sunscreen). It stands for Sun Protection Factor and is "a measure of how much solar energy (UV radiation) is required to produce a sunburn on the skin (i.e., in the presence of sunscreen) relative to the amount of solar energy required to produce a sunburn on unprotected skin," according to the FDA. Okay, so does that mean SPF is actually a math equation? No, so you can put down your calculator. Here are the key differences between SPF and sunscreen so you can understand all you need to know to lather up and protect yourself from the sun.

Sun Protection Factor — aka SPF — is how sunscreen manufacturers indicate how much protection their sunscreen will be able to offer when you wear it while exposed to solar power (UV radiation). The higher the SPF, the more protected you'll be from sunburns. John Hopkins Medicine recommends wearing sunscreen with an SPF of at least 30 for everyday use. If you're planning on spending lots of time outside, John Hopkins says that the ideal sunscreen has an SPF of 60 or higher.

While sunscreen always has SPF, not everything that has SPF is classified as sunscreen. Makeup with SPF is not enough to protect your skin. Even if your foundation has SPF, you'll still need to wear sunscreen underneath it. "Don't rely on makeup for the best source of SPF as it's notoriously unreliable in terms of the level of protection," New York City dermatologist Dr. Bruce Katz told Makeup.com. "Plus, makeup isn't always applied evenly and comes off easily, decreasing optimal coverage. You want to wear sunscreen underneath your foundation — it actually provides a better base for your makeup application."

Broad-spectrum SPF refers to the sun protection factor that guards your skin against UVB and UVA rays. According to SkinCancer.org, UVB rays are those that are most likely to cause skin cancer. Meanwhile, UVA rays are the ones responsible for making your skin sunburned, tanned, and wrinkly.

Although SPF is a measurement of how well a sunscreen will protect your skin from UV radiation, that metric isn't always consistent depending on skin tone, the amount of time you're outside, and the intensity and amount of solar energy exposure. According to the FDA, one popular misconception about SPF that many people fall prey to is the idea that SPF relates to how long you're outdoors. No matter how high the SPF is, according to the FDA, you should be reapplying your sunscreen every two hours and more frequently if in water or sweating.

The higher the SPF, the more protected you'll be during that two-hour block. According to Very Well Health, SPF 30 blocks 97% of UVB rays (the ones responsible for damaging cells and triggering skin cancer), SPF 100 blocks 99% of those UVB rays. You'll still want to reapply your sunscreen, but knowing what the SPF means can help you make sure you know how protected you are while wearing it.

The FDA advises that you should apply sunscreen at least 15 minutes before you go outside to allow time for the product to be at its most effective by the time you're in the sun. Some commonly forgotten spots to be sure to include are the ears, nose, hands, back of the necks, tops of feet, and hairline.