What Is SPF And How Does It Work

What Is SPF And How Does SPF Work?

  Sunscreen helps protect your skin from UV rays, which cause sunburn and the accumulation of cell-damaging free radicals. SPF is one aspect that determines the effectiveness of a sunscreen.


SPF stands for Sun Protection Factor. It measures the level of UVB protection a sun protection product will give you and ranges from 1 – 90.

NIVEA sun protection products also protect you from UVA rays.


The SPF indicates the length of time that your skin is protected from sunburn, depending on your skin type.

To help you understand a bit better, if you start getting sunburned after five minutes in the sun without any sunscreen, applying a sunscreen with an SPF of 30 would protect you for 30 x five minutes (or 150 minutes) before you begin to burn.

Depending on your skin type, location and the time of year, the time it takes for you to begin getting burned is between five to 30 minutes, on average.

There are some other factors that will also affect your level of protection, such as:

  • How much sunscreen you apply
  • The weather conditions
  • How much you sweat
  • How long you swim and how well you dry off afterwards
  • Your skin type

How Does SPF Work


As you know, sunscreens vary in SPF.

A high SPF extends the amount of time you can spend in the sun while protecting your skin. SPFs are broken down into four levels:

  1. Low (4, 6, 8, 10)
  2. Medium or Moderate (15, 20, 25)
  3. High (30, 40, 50)
  4. Very high (50+)

We recommend using a sunscreen with an SPF between 15 and 50, depending on your skin type and skin tone.

No sunscreen can block all UVB rays. However, in terms of percentages, a sunscreen with:


These differences might seem small but over a lifetime, it all adds up and every little bit of protection helps.

Remember to apply your SPF 50+ sunscreen just as regularly as your SPF 30 or SPF 15 to ensure continuous protection throughout the day. We recommend that you reapply sunscreen every two hours regardless of its SPF.

SPF 15

SPF 15 will filter out approximately 93% of the UVB rays

SPF 30

SPF 30 keeps out about 97% of the UVB rays

SPF 50

SPF 50 blocks out around 98% of the UVB rays

Always read the label. Follow the directions for use.