How Much Sunscreen Do You Need?

The scoop on the right amount of sunscreen to use each season. (Photo: Getty)

Every spring, the warm weather arrives and it’s time to reach for that trusty stash of sunscreen. You know, the bottle left over from the prior summer? It seems wrong not to hold onto it, but according to a top dermatologist, leftover sunscreen isn’t a great thing: it could mean you didn’t use enough.

“You should use up a whole 8 ounce bottle every weekend when applying it to your whole body,” explains Dr. Neal Schultz, a New York City based dermatologist and founder of DermTv.com and creator of BeautyRx. “This assumes a first application and three reapplications each day, with each application being about 1 ounce,” says Schultz. Of course, you should be wearing sunscreen year round, so if you have any sunscreen leftover at the end of the season, Schultz recommends using it to cover your face, hands, neck, and any areas or your body that are exposed daily throughout the year.

How much sunscreen should you be using? Schultz recommends applying one ounce from head to foot if you are hitting the beach in a bathing suit. “If you apply smaller amounts, the sun protection factor is diminished to the square root of the factor: SPF 50 becomes SPF 7, and SPF 15 goes all the way down to SPF 4,” he says. For everyday, when your face, neck and hands are exposed, you should be applying a dollop about the size of a quarter. “Either way, remember it’s crucial to reapply every 2-3 hours and after you swim or sweat,” says Schultz. When it comes to sunscreen sprays—be cautious. Schutlz says there is no way to know how much is enough when using a spray. “I see the worst burns on areas completely missed by sunscreen sprays.”

Get ready to stock up for the summer season. For your whole body, Schultz recommends you should use at least 4 ounces per day with four applications—that means one 8 ounce bottle will only last the weekend. With 17 weekends between Memorial Day and Labor day, you’ll need at least 17 8 ounce bottles to get you through the season—even on rainy or cloudy days. “Physical [chemical-free] sunscreens work better and faster than chemical sunscreens by reflecting dangerous UV radiation from your skin so it can’t damage you,” says Schutlz. “They’re also much better for sensitive skin.”

When it comes to wearing sunscreen, no one is exempt says Schutlz. “Everyone – regardless of skin tone or ethnicity – needs to wear sunscreen.”