What does SPF 50 sunscreen mean? (2024)

FAQs

What does SPF 50 sunscreen mean? ›

A sunscreen with SPF 50 on its label means it has been tested to block up to 98 percent of the sun's UVB rays and allows two percent of UVB to reach your skin.

Sun Protection Factor (SPF) is a measure of protection sunscreen gives against UVB radiation. The rating tells you how long the sun's UV would take to redden your skin compared with using no sunscreen. For example, in theory SPF50 would take you 50 times longer to burn than if you use no sunscreen.

But the extra protection is negligible. Properly applied SPF 50 sunscreen blocks 98 percent of UVB rays; SPF 100 blocks 99 percent. When used correctly, sunscreen with SPF values between 30 and 50 offers adequate sunburn protection, even for people most sensitive to sunburn.

SPF50 is estimated to filter 98% of UVB radiation with 1/50th (2%) reaching the skin. Both can provide excellent protection if they are applied properly. SPF50+ sunscreen still needs to be applied liberally as with any other sunscreen – see our recommendations below on how to apply it properly.

According to the interpretation of the meaning of SPF, SPF 50 sunscreen means: The time to resist the harmful effects of UVB rays when used on the skin is about 500 minutes. The ability to block the penetration of UVB rays into the body is up to 98%.

The SPF number tells you how long the sun's UV radiation would take to redden your skin when using the product exactly as directed versus the amount of time without any sunscreen. So ideally, with SPF 30 it would take you 30 times longer to burn than if you weren't wearing sunscreen.

It has been found that in average conditions, a sunscreen with SPF 50 will last for approximately 3 to 4 hours⁹. If you're on the move, sweating, or in a place with a particularly strong UV index, it is recommended to apply SPF 50 sunscreen every 2 to 3 hours.

Usually an SPF of 30 will suffice, she said, but people who are in the mountains, at snow level, or on the water may want to use SPF 50 or 70. For best protection, she said, use a shot glass' volume of sunscreen, approximately 1.5 ounces, every two hours on exposed skin.

The SPF (sun protection factor) in sunscreen lets you know how much time it will take for the sun to burn your skin after exposure. If you use sunscreen SPF 50, it means your skin will probably take 50 times longer to burn as compared to not using sunscreen.

Shotter confirms. “As a rule of thumb, do not use less than SPF30. In the summer months use SPF50 and reapply every few hours throughout the day if you are outside in the sunshine.” (Wearing make-up? No problem: keep a SPF mist in your bag.)

Why shouldn't you wear sunscreen every day? ›

If you were to use sunscreen every day, your body would continuously absorb any chemicals it contains, potentially much faster than your body can filter and excrete them. Even if you avoid the most harmful chemicals like benzene and oxybenzone, you may still be absorbing chemical preservatives, fragrances, and more.

The best type of sunscreen for your face is one that you will use every single day—no ifs, ands, or buts. The most important thing to remember is that you should always choose an SPF of 30 or higher (anything below that won't protect much) and make sure the formula protects against UVA and UVB rays.

By Karl Roos - January 1, 2024. "Properly applied SPF 50 sunscreen blocks 98 percent of UVB rays, while an SPF 30 sunscreen blocks 97 percent of sunburn rays – the difference being one percentage point." SPF stands for Sun Protection Factor.

The SPF rating only refers to UVB rays. An SPF 15 sunscreen blocks 93% of UVB radiation, and SPF 30 blocks 97%. After that, the difference in protection is small. SPF 50 blocks 98%, and SPF 100 stops 99% of UVB rays from reaching your skin.

For day-to-day use, pick a sunscreen with an SPF of at least 30. If you spend time outdoors, choose a product with SPF 60 or greater.

Benefits of sunscreen SPF 50

It blocks 98% of UVB rays, which are responsible for causing sunburn, and also protects against UVA rays, which can penetrate deep into the skin and cause long-term damage. Sun damage can cause premature aging, such as fine lines, wrinkles, and age spots.

A 30 SPF sunscreen would provide 30 times the protection of no sunscreen." That means 30 times longer before you start to burn, or in this case, 300 minutes.

The SPF rating only refers to UVB rays. An SPF 15 sunscreen blocks 93% of UVB radiation, and SPF 30 blocks 97%. After that, the difference in protection is small. SPF 50 blocks 98%, and SPF 100 stops 99% of UVB rays from reaching your skin.