How much sunscreen do you need to protect your skin?

Image source, Getty Images Published 7 May 2018 Updated 22 June 2026 Sunscreen protects your skin from the damaging effects of UV radiation, and can help prevent skin cancer. But experts warn that many people do not use enough, or apply it correctly. How does the sun damage your skin? Sunburn is a clear sign that your skin has been damaged, but you do not actually need to burn to sustain skin damage. The cause is UV (ultraviolet) radiation emitted by the Sun. Some exposure to UV radiation is beneficial, because it enables our skin to produce essential vitamin D. This is important for the function of bones, blood cells and our immune system. But too much can cause premature ageing and lead to skin cancer. The number of new melanoma skin cancer cases diagnosed in the UK in a year has risen above 20,000 for the first time. The charity Cancer Research UK says too much exposure to UV - from sitting in the sun and sunbeds - is part of the cause, with an estimated nine in every 10 cases thought to be avoidable. Too much sun can also damage your eyes. What is the UV Index and how does it work? The UV Index is a measure of UV radiation used around the world. It starts at zero and can rise above 10. According to Cancer Research UK , external , if the UV index is three or above, you should consider using sunscreen and covering up. Higher readings require more protection. Levels of UV radiation vary throughout the day, with the highest readings over a four-hour period when the sun is at its highest - usually from late morning to early afternoon. UV levels are part of many weather forecasts, including those from BBC Weather and the Met Office , external . What are UV levels and how can you protect yourself? Published 22 June 'Mum was killing me': England's Rice on World Cup heat - and his sunburn Published 11 June How much sunscreen do you need? The NHS says most people do not apply enough sunscreen. It recommends that adults use around six to eight teaspoons of sunscreen , external if they are covering their entire body. Sunscreen should be applied to all exposed skin, including the face, neck and ears - and head if you have thinning or no hair - ideally 30 minutes before you go out into the sun. It should be reapplied every two hours, or sooner if you sweat a lot, have been in water, or after drying yourself with a towel. This is the case even if the sunscreen says it is water resistant, or describes itself as long-lasting. However, no sunscreen provides absolute protection from UV radiation. So, you should wear trousers or skirts with a fabric that does not allow sunlight through, a top with long sleeves, a sun hat and sunglasses. Spend time in the shade during the hottest part of the day. Image source, Getty Images How can children be protected from the sun? You should take extra care to protect babies and children as their skin is much more sensitive to sun damage. The NHS says children younger than six months should not spend any time in direct sunlight