Sunscreen - How much is enough?

Everyone agrees that it is important to apply sunscreen in order to stay safe in the sun, but just how much sunscreen do you really need to apply?

There is a mountain of evidence that shows typically we do not apply enough. The optimum levels of application are worked out in controlled lab conditions and we know daily life is anything but controlled, so how do you make sure you apply enough?

Firstly, work out what SPF value you should be using. SPF stands for Sun Protection Factor and can be worked out using this simple equation:


However, your sunscreen will only give you the stated level of protection if it is in date and you are using a standalone SPF product (moisturiser/SPF combos don’t count here), so keep an eye on the expiration date as it indicates when the product becomes ineffective and should be discarded. Ultrasun sunscreens last for 2 years after opening, which make them extremely good value for money.

 How much sunscreen should you actually apply?

There is an actual (read: tedious) prescription for applying sunscreen to the body. It’s called the Rule of Nines to and related to eleven specific areas of the body.  We think it sounds like a fight scene from Game of Thrones and sunscreen never needs to be that complicated!


Our much simpler advice -  apply 2 fingers worth (index and middle) of sunscreen to each of the 11 areas of the body and that will give required amount of sun protection to key you safe. If you prefer using a spray sunscreen all over the body, then make sure you apply until an even sheen appears on the skin.

When to apply?

We know there are never enough hours in the day, but to get the most protection from your sunscreen

apply  at least 15 minutes before heading outdoors and remember to reapply during the day. On the face you can use a powder sunscreens like ColourScience over your make up as a touch up.

It’s a common misconception that once you’ve applied sunscreen once, you’re protected throughout the day. The truth is sunscreen needs to reapplied every 2 hours, especially if you’re out in the sun or exercising as it tends to degrade over time with exposure to sun rays, water, sweat and heat. Our Ecooking sunscreen cleverly tells you how much degradation happens following activity like swimming for example. Pretty handy!

Lastly, remember that a high factor sunscreen doesn't necessarily mean high protection - SPF 30 blocks nearly 97% of UVB radiation, SPF 50 blocks about 98%, and SPF 100 blocks about 99%. The difference is negligible so which ever factor you use, it’s still key to reapply where possible, even when it is cloudy, especially to protect your skin from the ageing elements of the sun.

According to The Skin Cancer Foundation, on a cloudy day there is still a chance of getting up to 80% of the sun's harsh effects, not to mention the damage the sun does to collagen in your skin as well as contributing to hyperpigmentation and worsening lines and wrinkles.

It’s important to use sunscreen, but to make it worth your while in the long term, stay switched on to ensure you are applying enough.