How Much Sunscreen Should You be Applying? Just Ask Mark Zuckerberg

Sun Protection

Apr 14, 20237 min read


  • Sunscreen is essential every day, even in cold weather or when indoors or in cars, as UV rays can still cause damage.
  • Most people do not use enough sunscreen, with only 25-50% of the recommended amount applied, leading to sunburns despite application.
  • Two milligrams of sunscreen per square centimeter of skin is recommended, equivalent to 1 shot glass for the face and body, with reapplication every two hours, more frequently when outdoors or after swimming, sweating or toweling off.
  • Tropic Labs' Smart Screen SPF 22 offers broad-spectrum UV protection, including skin-loving antioxidants for a tan without extreme white cast. Still, other sun-protective measures such as wearing a hat and sunglasses and avoiding peak times outdoors are recommended.


Every year around this time, painfully embarrassing photos of a HEAVILY sun-screened Mark Zuckerberg surface and make their way around the internet. If you’re like us, then you probably can’t help but wonder… is he actually onto something? 

Wrinkles, sunspots, and skin cancer are just a few of the many dangers that come with not protecting your skin regularly. Even in cold weather, you need to wear sunscreen every day to protect yourself from UV damage caused by the sun. 

But you may be wondering... does less sun exposure mean you need to apply sunscreen less frequently? Does more exposure to the sun mean you need a higher SPF? And how much sunscreen should you be wearing? 

Well, if you’re reading this, you’re probably like most people and do not apply enough sunscreen. According to the American Academy of Dermatology, most people only use 25-50 percent of the recommended amount of sunscreen, which is why sunburns can still occur despite sunscreen application. [1] If you’re confused about how much sunscreen you should apply, when to put it on, how often to reapply it, keep reading!


When to Apply Sunscreen

Our general rule of thumb at Tropic Labs is to treat every day as a high sun exposure day because, in reality, all UV rays can be damaging. It is essential to keep in mind that we can still get sun damage on a cloudy or cold day.

And on that subject, few people realize they can still get sun damage indoors or in their cars because windows are hardly treated with filters for UVA and UVB rays.

We suggest you apply sunscreen every day to dry skin. Use sunscreen at least 15 minutes before going outdoors to let the ingredients fully bind to the skin (and rub it in until you can’t see the product.)  Keep in mind that even though clothing provides a thin barrier between your skin and the sun’s rays, most UV rays can penetrate through clothing. The best way to make sure you get full coverage is to apply your sunscreen before getting dressed and then reapply again to all exposed skin.


How Much Sunscreen Should I Use?

Regarding how much sunscreen you should use, most dermatologists recommend applying approximately two milligrams of sunscreen per square centimeter of skin. This is the equivalent of 1 shot glass (a single ounce) of sunscreen to the face and body. You can allocate about a ¼ teaspoon dollop to your face and neck region. If you're using a sunscreen spray, then any exposed skin should be coated until an even sheen appears on the skin.

Some people tend to forget to apply sunscreen on the back of the ears, lips, exposed scalp, back of the neck, around the eyes, and the tops of the hands and feet.

Just to be super clear, you should always be using a 'broad spectrum' sunscreen. This means it will protect against UVA rays (which cause wrinkles and age spots) and UVB rays (which cause sunburns.) Now, we understand that the sun care industry is a very polarized space! On the one hand, you have those who diligently apply sunscreen every single day as recommended. On the other hand, you have those dangerously lathering up in oil hoping for that perfect tan. If protecting your skin while getting a tan is important to you, Smart Screen was meant to bridge this gap! We've done our best to formulate a water-resistant mineral SPF 20 that is loaded with skin-loving antioxidants that help you achieve a beautiful tan and doesn't leave an extreme white cast, (we’re looking at you Zuckerberg.) 

If you’re interested in learning more about the sun's rays, or using sunscreen while also trying to achieve a tan, check out our blog post, What UV Index is Best For Tanning.


How Often Should I be Reapplying Sunscreen?

Remember that sunscreen needs to be reapplied every two hours, despite being indoors or outdoors. When outdoors, reapply sunscreen more frequently, approximately every eighty minutes, or after swimming, sweating, or toweling off. No matter how much sunscreen you apply, the SPF should be 15 or higher for adequate protection. Tan Smart offers broad-spectrum UV protection using the mineral UV filter zinc oxide at a concentration of 15.6%. It has been approved by the Food & Drug Administration as a sun protection product with an SPF value of 20. Still, as always, Tropic Labs recommends you use other sun-protective measures such as wearing a hat, UV filtering sunglasses and avoiding peak times outdoors. Remember, no sunscreen is a suit of armor!




1. “Sunscreen FAQs.” American Academy of Dermatology,

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