How much sunscreen do you need to protect your skin?

How much sunscreen do you need to protect your skin?Image source, Getty ImagesPublished7 May 2018Updated 22 June 2026Sunscreen 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?Published22 June'Mum was killing me': England's Rice on World Cup heat - and his sunburnPublished11 JuneHow much sunscreen do you need? The NHS says most people do not apply enough sunscreen. It recommends that adults use around...