. . . it’s almost certainly more than you thought, as this clever ‘coin formula’ reveals HOW MUCH SUNCREAM YOU REALLY NEED

The sight of lobster-red skin that’s been caught out by a surprisingly sunny weekend is as much a part of a British summer as 99s, Wimbledon and windswept picnics.

That’s in spite of the frequent warnings about the health dangers of sunburn — chiefly an increased risk of skin cancer.

‘In my experience, the majority of people still don’t wear high factor suncream when they’re in this country,’ says Justine hextall, a consultant dermatologist at the Tarrant street Clinic in Arundel, West sussex.

‘however, I’ve seen plenty of patients with skin cancer who’ve been abroad infrequently, or in some cases have never left the UK. even if you don’t burn easily — or have darker skin — you still need to protect yourself.’

Almost a quarter of Britons say they never use sunscreen, even while on a hot holiday, according to a 2017 YouGov survey.

even if you do use it, the chances are you’re not getting the true sPF stated on the bottle. (sPF stands for sun protection factor and indicates the level of protection against sunburn a product offers — anything above 30 counts as high.) But if you’re using factor 30, the protection is likely to be closer to factor 15 once you’ve applied it.

‘To truly get the sPF on the bottle we need to apply 2mg of cream for each square centimetre of skin, as this is what they apply in lab tests,’ explains Dr hextall.

‘however, this is a very thick layer, and on average we apply less than half of this. so the actual applied sPF will be half of the intended. Always start high with sPF— or go for double what you think you need.’

so how much sunscreen do you need to apply? It can be difficult to judge, as there’s such a vast range of products, including lotions, mousses, sprays and gels, says Bav shergill, a consultant dermatologist at Queen Victoria hospital in east Grinstead.

‘Because of this, I’d always suggest checking what the manufacturer recommends for your particular product,’ he says.

As a general rule, the British Association of Dermatologists says you need at least six full teaspoons of cream to cover the body. This means for a week’s holiday you should pack at least a 200ml bottle of suncream per person, says Dr hextall. ‘It’s a lot more than you realise.’

here, based on Dr hextall’s advice, we reveal how much suncream the average adult needs for each part of the body . . .