How much SPF do you need in your sunscreen?

Prevent sunburns and reduce your risk of skin cancer by selecting a sunscreen with the right Sun Protection Factor (SPF). What is SPF? SPF refers to the sun protection factor, or how well a sunscreen blocks harmful UVB rays, which cause sunburn and play a role in skin cancer. read more

To achieve the Sun Protection Factor (SPF, which protects against the sun’s UVB radiation) reflected on a bottle of sunscreen, you should use approximately two milligrams of sunscreen per square centimeter of skin. read more

Conversely, if you are skin type 1 and you are using an SPF of 15, you can stay out in the sun for 20 x 15 = 300 minutes (5 hours). After that you would need to reapply your sunscreen if you want to stay out in the sun further. read more

Ade Adamson: The amount of UVB radiation blocked by SPF 15, 30, 50, 100 sunscreen is 93 percent, 97 percent, 98 percent and 99 percent, respectively. So, doubling the SPF does not double the amount of protection one gets from sunscreen. read more