The exact amount of SPF you need to apply everyday

You probably need to apply more SPF than you think. (Getty Images)
You probably need to apply more SPF than you think. (Getty Images)

We know we need to be wearing SPF every day, but how much we need to apply still seems to be baffling us Brits.

Research from the British Skin Foundation shows that a whopping 67% of us aren't using enough sunscreen. A further study found that overall, consumers only use about 20 to 50% of the amount of sunscreen needed to achieve the numbered protection on the bottle

But rubbing in the right amount is a huge part of measuring how effective suncream is and how well it is keep us safe from the sun's harmful rays.

"It's common for people to think SPF is similar to a moisturiser, believing if they just cover their face, that's enough," explains Dr Ahmed El Muntasar GP and aesthetics doctor. "But in reality the quantity is very important."

Dr El Muntasar says we should be applying the correct "dosage" of sunscreen in order to be protected.

"You know, when you go to the GP and they prescribe you medication to take - a certain number of milligrams or the number of doses? Sunscreen application is similar to this. It is a set quantity we need to apply and the amount is very, very important."

But how do we know how much we need to be applying?

The recommended amount of sunscreen is two milligrams per centimetre square of skin. But, in reality that's pretty difficult to measure.

Some experts say the amount for your entire body should add up to roughly a shot glass of product, but again that's not something we're likely to carry around with us.

Thankfully, however, "the two finger rule" provides a simple yet effective guide for knowing exactly how much sunscreen we need to apply to our face and neck.

Brits are unsure how much SPF they need to be applying. (Getty Images)
Brits are unsure how much SPF they need to be applying. (Getty Images)

The two-finger method is a SPF application technique that involves squeezing sunscreen up to the length of two fingers (the distance from the crease of the palm to the tip of the index and middle fingers). The idea is this will be enough to cover the area on your face and neck.

While the rule has been circulating on social media, it's actually not all that new and stems from a dosage guide published in 2002 by a group of New Zealand doctors.

The guide came following studies revealing consumers are applying much less sunscreen than the recommended amount, which has a knock-on impact on protection, with typical application rates achieving a sun protection factor of perhaps one third of that stated on the product.

To counter this the researchers recommended we should be applying the two-finger lengths of sunscreen to eleven different body parts.

The different body parts are:

  • The head, face, and neck.

  • Left arm.

  • Right arm.

  • Upper back.

  • Lower back.

  • Chest (upper torso area).

  • Stomach (lower torso area).

  • Left upper leg and thigh.

  • Right upper leg and thigh.

  • Lower left leg and foot.

  • Lower right leg and foot.

Experts recommend applying two fingers of sunscreen for your face and neck. (Getty Images)
Experts recommend applying two fingers of sunscreen for your face and neck. (Getty Images)

"The two finger rule is great for people to understand the quantity needed," explains Dr El Muntasar. "For the longest time, people were talking about using just a pea size amount or different amounts in different countries but your fingers are proportionate to your face. So ultimately, using that two finger amount is a little bit more specific and easier to follow."

While some people do think it’s a lot of SPF to rub in, Dr El Muntasar recommends dotting the SPF everywhere and blending it in with one finger first, then going back in with the second finger.

Another sunscreen hack, especially amongst the skincare community on social media, is to measure out about 1/2 teaspoon tools of SPF for your face and neck.

"This measurement aligns with dermatologists’ recommendations and ensures you’re applying enough product to get the full SPF protection," explains Amy Ford, founder of Hello Sunday.

The two-finger rule allows an individual to receive the sun protection level mentioned on the product and not following it means people could have a false sense of security about being fully protected from the sun.

"People will stay in the sun for a long period of time, thinking that they're protected. However, if they're not used the right amount, they've not reached the SPF that's written on the bottle," Dr El Muntasar explains.

"Similarly when you know there's SPF in makeup for example, people think that they've reached SPF 30, but you probably see in fine print that you need to apply three layers of foundation to reach that, so it's an extremely high quantity actually to reach that full coverage."

The problem is not applying enough SPF can lead to some pretty serious risks.

"Most notably, inadequate protection increases your risk of skin cancer, including melanoma," warns Ford.

"Additionally, not using enough SPF can contribute to premature ageing of the skin, leading to wrinkles, fine lines, and pigmentation."

And even if you're following the two finger rule, that doesn't mean you can skip reapplying. "You should reapply every two hours, or more often if you've been playing sports, sweating or swimming," she adds.

There are some pretty serious risks of not wearing enough SPF. (Getty Images)
There are some pretty serious risks of not wearing enough SPF. (Getty Images)

Ford says the most common errors are forgetting areas like their ears, neck, lips and hands which are highly susceptible to sun damage.

But not applying SPF every day or when the weather is overcast is another sunscreen faux pas.

"The biggest challenge is overall awareness and in the UK people often think it isn't warm enough here so SPF is only necessary on a summer holiday or during the warmer months," Ford explains.

Dr El Muntasar another mistake he sees is people not paying attention to the number that's on the SPF and using an SPF 15 or SPF 10.

"Something that low that actually won’t provide much protection at all," he adds.