How long does spf35 protect you from the sun? The difference between spf35 and spf50 is not as big as you think

For many girls who pay attention to skin care, they will never forget to use sunscreen when going out in summer. After all, only by doing a good job of sun protection can you avoid premature aging of your skin. So how many hours can the SPF35 sunscreen on the market provide sun protection? Is it really accurate to judge the duration of sun protection based on the SPF level?

How many hours does spf35 protect you from the sun?

SPF35 means 525 minutes of sun protection. Based on the time it takes for Asians to get sunburned, the theoretical sun protection time is equivalent to 8.75 hours. However, there is a misunderstanding here. Since there are many factors that affect the sun protection effect of sunscreen, SPF35 sunscreen cannot maintain 8.75 hours of sun protection in real life.

When we apply sunscreen, there is a possibility of insufficient use, uneven application, missing detailed parts, and sweating. In addition, the ultraviolet intensity is very high when girls are on the beach or in the mountains, which will also affect the sun protection time of SPF35 sunscreen ( in fact, no matter how high the SPF value of the product is, it cannot achieve the theoretical sun protection time ). Therefore, when girls use SPF35 sunscreen indoors, it is best to reapply it every 3 hours; and when they are outdoors for 1 hour, they need to reapply SPF35 sunscreen.

SPF35 sun protection time calculation formula

SPF refers to sun protection factor, which is the abbreviation of Sun Protection Factor in English. Indicates the sun protection effect of sunscreen products, which is determined by the minimum erythema dose of the skin (the average skin color in Asians is sunburned in 15 minutes).

Under laboratory conditions that exclude factors that affect the sunscreen effectiveness of sunscreen, the sunscreen time for SPF35 sunscreen can be simply estimated as: 15 minutes * 35 = 525 minutes = 8.75 hours