How much sunscreen should you use? – Beautiful with brains

How much sunscreen should you use on your face and body each day to protect your skin from UV rays? I thought high FPS was enough. As long as I apply SPF 30 or more, no matter how much I apply, my skin will be well protected even in the scorching summer months. Boy, how wrong was I!

No matter how high your SPF is, quantity matters too. Don’t get me wrong, of course you want a high SPF. Anything below 30 is pretty much useless. BUT, here’s the catch: you could slather on SPF 100, but if you skimp on the application because the texture is greasy and unpleasant, it won’t protect your skin as well as you think. And then you wonder why you got sunburned when you were so careful!

It’s not the sunscreen’s fault. And frankly, it’s not your fault either. Everyone tells you to apply sunscreen generously but, in reality, how much does it cost? ! A thick layer? Half a teaspoon? You do a quick Google search and everyone has a different answer…. I’ve spoken to many dermatologists over the years and here’s how to answer the question, “How much sunscreen should you apply to your face and body each day?” Let’s find out:

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How much sunscreen do you really need to use on your face?

Did you know there’s a difference between how scientists test the effectiveness of sunscreens and how people use sunscreens in everyday life?

“To get the protection labeled on the product, you have to replicate the application they do in the lab, which is 2 milligrams per square centimeter for the average person. That translates to half a teaspoon on face and neck combined — a quarter of a teaspoon each” says board-certified dermatologist Ranella Hirsch. “People actually use about half that amount.”

If it’s too complicated to remember, here are some practical tips to certified dermatologist Marisa Garshick: “For the face, it is recommended to apply a dollop the size of a nickel – the equivalent of two finger lengths, which is also equivalent to half a teaspoon, on the face and neck combined .” It doesn’t matter if you use chemical or physical sunscreen, by the way. Always apply exactly this amount.

What if you use a stick sunscreen? I’m not a fan, but if you must use one, “apply four swipes back and forth, then swipe it in after for even coverage,” Garshick says. And the sprays? I do not recommend at all. They’re transparent, so it’s impossible to see if you’ve skipped a bit of skin. But, if you insist on using them, apply them until there is a visible sheen on the skin (you need to make sure every inch of skin is covered!).

How much sunscreen do you need for your body?

You should always apply 2 mg per cm2 because this is how scientists test the effectiveness of your sunscreen. But how much does it cost your body? When you go to the beach, you just want to apply sunscreen, not do math equations in your head, you know what I mean?

2mg per cm2 translates to “1 teaspoon per arm and leg each, front and back“, Hirsch said. What about the whole body? This time, Garshick comes to the rescue, explaining that it’s “the equivalent of a body shot glass or two tablespoons.”

Related: Are you applying sunscreen the right way?

How much SPF do you get if you apply less?

Rumor has it that if you apply half the amount of sunscreen you need to stay safe in the sun, you’ll only get the protection of the square root of the SPF. So an SPF 70 turns into an SPF 8.4! Scientists calculated it with the Beer-Lambert law, a physical law that says protection decreases exponentially with less sunscreen. Michelle from Lab Muffin has a great article on this.if you are interested in the science behind this law.

But, I’ll keep it simple for you. Scientists have used this law to theoretically judge the amount of application affected by SPF. Until someone, somewhere decided to put this law to the test. Do you know what they discovered? The latest research shows that with less application, SPF decreases linearly, not exponentially.

In other words, applying half the recommended amount gives you half the SPF. So an SPF 50 becomes an SPF 25. That’s more like it, isn’t it? But don’t use that excuse to apply less sunscreen now. What’s the point of buying SPF 50 if you’re not getting the full protection?

Best Sunscreen Picks

Not sure which sunscreen to use? Here are my favorite sunscreens for every skin type and need:

• Drunk Elephant Umbra Tinte Physical Daily Defense SPF 30 ($36.00): A tinted mineral sunscreen that protects you from all UV rays without leaving white marks. Best suited for dry skin. Available at Boots, cult beauty, NK SpaceAnd Ultimate.
• La Roche Posay Anthelios Clear Skin Dry Touch Sun Cream SPF 60 ($19.99): Ideal for oily skin, this lightweight sunscreen provides broad-spectrum protection and absorbs excess oil for a matte finish. Available at Boots, dermstore, La Roche-PosayAnd Ultimate.
• Paula’s Choice Defense Essential Glow Moisturizer SPF30 ($26.40): Suitable for all skin types, this tinted mineral sunscreen provides broad-spectrum protection, fights premature wrinkles, and dries to a luminous finish. Available at cult beauty, Paula’s Choice, Sephora, SelfridgesAnd NK space.
• Shiseido Ultimate Sun Protection Lotion Wide Spectrum SPF 50+ WetForce for Sensitive Skin & Kids ($42.00): A broad-spectrum, high-SPF protective formula that’s gentle enough even for children and sensitive skin. It is water resistant for up to 80 minutes. Available at Sephora And Ultimate.
• Super goof! SPF 40 Mineral Matte Screen ($38.00): A mineral sunscreen that provides broad-spectrum protection and dries to a silky matte finish. It also minimizes the appearance of pores. It is best suited for oily and combination skin. Available at blue mercury, Nordström, TurnAnd Ultimate.
• Ultrasun Ultra Sensitive Very High SPF50+ Extreme Formula (£30.00): This sunscreen uses the next generation of chemical filters to provide broad-spectrum protection without irritation. Also suitable for sensitive skin. Available at Boots, SephoraAnd Spacen K.

The essential

If you want the protection that SPF promises you, you need to apply sunscreen the same way researchers test it to determine that SPF in the first place. Simply put, you should use 1/2 teaspoon for your face and neck and a shot glass for your whole body.

About Gio

Hi, I’m Gio. I’m a no-nonsense, like-it-like skin coach and writer, with a mission to help you achieve your best skin day ever — every day. I bust skincare myths and demystify marketing jargon to help you figure out what’s worth splurging on and what’s best left on the shelf – using science, not hype. I also offer skincare consultations to help you create the best skincare routine for your unique needs.