SPF Meaning: Here’s What It Means and How to Use It

You’ve likely seen the acronym SPF before, but do you know what it stands for? Read on to discover the meaning of SPF and more.

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A day of fun in the sun is never complete without the goopy feel of sunscreen leaving white streaks across your rosy cheeks, but have you ever wondered about the meaning of “SPF” — the acronym that’s always stamped across the bottle? If so, you’re in the right place.

This guide will provide you with information on SPF, including what the acronym stands for, it’s meaning and more. 

Let’s get started!  

What Is the Definition of SPF?

According to the United States Food and Drug Administration (FDA), SPF stands for “Sun Factor Protection” and refers to a number on a scale for rating the degree of sunburn protection provided by sunscreens. The higher the SPF, the more protection it gives.  

There is a widely popular misconception that SPF correlates to time of solar exposure, but this is not the case. SPF is not directly related to time of solar exposure, but to amount of solar exposure. 

This means that the amount of solar energy that reaches your body for 15 minutes at around noon will be about the same as you would receive in 60 minutes at 9 a.m. In simpler terms, when the sun is high, exposure is four times as intense. 

Simply put, SPF is an indication of how much protection a sunscreen offers against sunburn. 

What Do Experts Recommend? 

The experts at the American Academy of Dermatology (AAD) recommend the daily application of SPF 30 or greater to all exposed skin. It’s also important that you choose a broad-spectrum sunscreen that is water-resistant. 

What Is Broad Spectrum SPF?

SPF only measures how much sunscreen will protect you from UVB rays, but what about the UVA rays? For total body protection against both UVB and UVA radiation, it’s important that you opt for a quality sunscreen that says “broad-spectrum” on the bottle. 

Even with a high SPF, if your sunscreen isn’t broad-spectrum, you won’t be protected from all of the sun’s harmful rays:

  • Ultraviolet A (UVA) rays have a shorter wavelength and are commonly associated with skin aging. 
  • Ultraviolet B (UVB) rays have a shorter wavelength and are responsible for sunburns.

What Are the Benefits of Broad-Spectrum Sunscreen?

Here’s the truth — if you’re not using a broad-spectrum sunscreen, you’re not fully protected from the sun. Other benefits of applying a broad-spectrum sunscreen include:

  • It can help prevent skin cancer. According to a recent study, daily use of an SPF 15 sunscreen has been shown to help reduce the risk of developing the skin cancers squamous cell carcinoma and melanoma. 
  • It combats premature aging. Believe it or not, 90 percent of skin aging is due to the effects of the sun. Fortunately, a broad spectrum can help you to prevent the signs of sun-damaged skin and aging by blocking UVA rays.
  • It can keep painful sunburns at bay. Thanks to the broad spectrum sunscreen’s ability to block UVB rays, it can help to prevent painful skin burning.  

What SPF Should I Use for My Skin Type?

When shopping for sunscreen, consider your skin type:

  • Skin type I — Pale (often with freckles), never tans, overly prone to burns; maximum sun exposure till burning 10 minutes. Recommended SPF rating: 30 to 50+
  • Skin type II — Pair-skinned individuals, often with light eye color, tans slowly but burns quickly; maximum sun exposure till burning 20 minutes. Recommended SPF rating: 20 to 50
  • Skin type III — Beige skin tone that burns on occasion but tans slowly; maximum sun exposure till burning 30 minutes. Recommended SPF rating: 15 to 30
  • Skin type IV — Light brown skin or olive skin, usually with dark hair and eyes, that tans quickly and rarely burns; maximum sun exposure till burning 40 minutes. Recommended SPF rating: 10 to 15
  • Skin type V — Dark brown skin with darker eyes and black hair, rarely burns; maximum sun exposure till burning 60 minutes. Recommended SPF rating: 4 to 8
  • Skin type VI — Very dark brown skin tone with black hair and dark eye color, very rarely burns; maximum sun exposure til burning 90 minutes. Recommended SPF rating: 4 to 8

If you need help figuring out what your skin type is, don’t hesitate to ask your dermatologist. They can also teach you the proper amount of sunscreen needed to prevent skin damage.


So, what does SPF stand for?

SPF is the acronym for Sun Protection Factor. It refers to a number on sunscreen labels that shows how long skin can be in the sun and maintain a relatively low risk for sunburn. The higher the SPF number, the higher the level of protection. 

That said, it’s important to keep in mind that no sunscreen — regardless of SPF — gives total protection, but “broad spectrum” sunscreens usually protect from both UVA and UVB rays. UV radiation can lead to skin damage and cancer; hence why it’s critical to keep your skin protected with broad-spectrum sunscreen lotion.

So, when you’re looking for sunscreen, be sure to consider your skin type and opt for a water-resistant, broad-spectrum product with an SPF of 30 or higher. This way you can look forward to both UVA protection and UVB protection.


  1. Sun Protection Factor (SPF) | FDA 
  2. What does the SPF rating really mean? | Australian Academy of Science
  3. Should you use very high SPF sunscreen? | MD Anderson