Applying sunscreen, especially on sunny days, is necessary to protect your skin from irreversible and potentially dangerous damage. But with different brands, different SPF numbers, formulas and application methods, it can be difficult to decipher how much sunscreen you need to maintain protection from the sun's strong rays.
Fortunately, most dermatologists recommend some basic tips for applying sunscreen to protect your skin from the sun's harmful rays: According to the American Academy of Dermatology (AAD), one of the most important things to know is how much sunscreen to apply. Although most people are aware that they need to reapply sunscreen, knowing how much to use is an integral part of the equation—especially since the application process varies with different formulas.
As a general rule for lotions and creams, the AAD recommends following the guideline of about 30 grams (say a half-closed fist). It may seem like a lot, but this amount of sunscreen is usually enough to cover the exposed areas of the body from head to toe.
What about protection sprays?
Sunscreen sprays are often considered less bothersome than creams, but that also means you have to be extra careful when applying to get the full amount of SPF—and not miss a spot on your body. The amount of coverage needed for a spray sunscreen to be effective requires at least six seconds of spraying on each spot—about four seconds longer than most people do.
Those who choose spray sunscreen should also apply the formula into the skin after spraying, especially if you're already outside, as the method can result in uneven coverage and unprotected skin, according to the AAD. With sunscreen that comes in a stick, which are often used to cover the face, it is recommended to apply generously to the entire face at least twice - and it is important to remember the ears and eyelids. As for SPF and the features to look for in a sunscreen, the AAD recommends choosing a sunscreen of at least 30 SPF or higher and offering broad-spectrum protection against both UVA and UVB rays—and applying 15 to 30 minutes before going outside.
When it comes to reapplying, the AAD recommends that people reapply their sunscreen at least every two hours outside, even when it's cloudy. If you swim or sweat, reapply more often. And before leaving home, make sure your sunscreen hasn't expired, as most formulas last about two to three years before they need to be replaced.