We’re constantly being told how important it is to wear sunscreen, but rarely are we told how to wear it. If you’ve ever wondered if you’re using sunscreen the right way, you aren’t alone. Maybe you’ve wound up with a nasty sunburn even though you took time to apply SPF. Read on for everything you need to know about proper sunscreen application.

The Difference Between Sunblock and Sunscreen

Although sunblock and sunscreen do the same things, they work a bit differently. Sunblock is a physical defense that uses minerals to absorb UV rays—and it starts working the moment you put it on. Sunscreen, however, is a chemical formula that works by absorbing into the skin. It needs to be applied at least 10 minutes before sun exposure to give it ample time to sink in.

The one thing that doesn’t vary between sunblock and sunscreen is sun protection factor (SPF). A sunblock and a sunscreen that are both rated at SPF 30 provide the same level of protection. Ultimately, between the two, there is no “better” product. The best sunscreen or sunblock is the one you use regularly.

How to Apply Sunscreen

Sunblock, as previously mentioned, works immediately, but sunscreen needs at least 10 minutes to absorb into the skin before sun exposure. Both products are applied the same way. The only difference is timing.

  • Shake the bottle well before you squeeze any sunscreen out. This mixes up all the particles and distributes them evenly in the container.An adult should use about 35 milliliters or 1 ounce (about 2 tablespoons) of sunscreen to cover their entire body, which is the same amount that would fit into a shot glass. It’s also about the same as an adult handful. Remember: most people don’t apply enough sunscreen, so it’s okay to use more than you think you should.Cover all of your skin that will be exposed to the sun. This includes often neglected areas like your back, ears, behind your knees and your legs.Continue to reapply throughout the day. If you’ve been in the sun for 30 minutes, you might want to reapply more sunscreen to get any places you might have missed. Definitely reapply 1 ounce of sunscreen at least every 2 hours. Always reapply 1 ounce of sunscreen after swimming, sweating or toweling off.

Get the Most out of Sunscreen

Sunscreen application isn’t a once and done deal, and just because you’re wearing sunscreen doesn’t mean you can’t get burned. Get the maximum sun protection possible by following these tips:

  • Always reapply. Reapplication is just as important as the first application. Set an alarm to help you remember.
  • It’s okay to apply more sunscreen than you should. Better to apply too much than not enough.
  • Wearing sunscreen doesn’t mean you’re immune to sunburn. You’re more likely to get a sunburn when the sun’s rays are at their most intense, during 10 a.m. and 4 p.m.
  • Watch your SPF. The SPF number tells you the percentage of the sun’s UVB rays that can be blocked by sunscreen/sunblock. For example, SPF 30 blocks 97% of the sun’s UVB rays, whereas SPF 50 blocks 98% of the sun’s UVB rays. There is no SPF level that blocks 100% of UVB rays.
  • Insect repellents can reduce a sunscreen’s SPF by up to 30%. If you’re using a sunscreen and insect repellent together, be sure to use them as two separate products rather than a combination product, and use a higher SPF and reapply more often.