What is the highest SPF value of sunscreen and how long can it protect against the sun?

When choosing sunscreen, you must first understand the SPF index. So what is the highest SPF value? How long does SPF sunscreen last?

What is the highest SPF value for sunscreen?

The sun protection factor of sunscreen products usually reaches up to SPF120. To increase the effectiveness of sun protection, you can increase the frequency of sunscreen application. When we are doing outdoor activities, it is generally recommended to use it again after 2 or 3 hours, so that the sun protection effect will be better. However, using sunscreen products with too high an index can easily deteriorate skin quality, causing problems such as dryness and enlarged pores.

How long does the SPF index provide sun protection?

The full name of SPF is sun protection factor. SPF means sun protection factor. SPF refers to the factor that protects against UVB sunburn, which refers to the time multiple of preventing sunburn. Generally, if you do not apply any sunscreen products, you will get sunburned after 10 minutes under the scorching sun. If you use SPF30 sunscreen, the time will be extended by 30 times, or 300 minutes. Moreover, the sun protection time will be shortened when sweating and producing oil. So even if the SPF index of the same sunscreen is the same, the time it takes for each person's skin to become sunburned will be different, which will also lead to different sun protection times.

If calculated based on 10 minutes, the SPF index of 15, 25, 30, and 50 can provide sun protection for 150 minutes, 200 minutes, 300 minutes, and 500 minutes respectively. PA+++ means that it can help our skin extend the possibility of getting tanned by about eight times under direct sunlight or ultraviolet rays. The more + signs there are, the greater the extension multiple. For example: one + is 2-4 times, two + is 4-8 times, and three + is 8 times or more.

The calculation method of SPF is as follows:

Generally speaking, without any sun protection, our skin will turn red after about ten minutes of exposure to sunlight. When you use SPF 15 sunscreen, it can help your skin stay in the sun fifteen times longer before redness appears.

SPF 15 = 15*10 = 150 minutes

SPF 20 = 20*10 = 200 minutes

SPF 30 = 30 * 10 = 300 minutes

SPF 50 = 50*10 = 500 minutes

SPF15 means it can extend the duration by 15 times, SPF25 means it can extend the duration by 25 times, SPF30 means it can extend the duration by 30 times, and SPF50 means it can extend the duration by 50 times.

Do you know how long the SPF index can protect you from the sun?