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SPF 101: Everything You Never Knew

SPF 101: Everything You Never Knew


We all know that sunscreen is important when it comes to actually being in the sun. What’s relatively new information is that the ‘when, the why, and the how’ is much more complicated than I originally thought.

Sun damage is the leading cause of aging in the skin and can lead to a myriad of different issues like scarring, brown spots, sun spots, hyperpigmentation, and melasma.

In fact, dermatologists say that if you do one thing for your skin- make it apply sunscreen daily.


If we can all agree that SPF and sunscreen are important, let’s try to simplify this complicated concept. Everyone, including people of color, need SPF – here’s why.

Why Everyone, Including People of Color, Need SPF?

What is sunscreen?

Sunscreen is the vehicle that delivers the SPF. This can be in the form of a lotion, spray, gel, or even powder. Think of it as a barrier between your skin and the sun.

What is SPF?

SPF stands for Sun Protection Factor and is usually represented by a number, anywhere from 2 – 100.

So the bigger the number the better right?

Not quite. In fact, research shows that there is actually little difference between SPF 30 and SPF 50.

Come again?

Sorry in advance, but let’s do some math.

The SPF number determines how much your sunscreen protects you from UV rays.

You calculate it like this: (1 ÷ SPF number) x 100. That tells you the percentage of UV rays that enter your skin. Subtract that from 100, and you’ll know how well your sunscreen protects you.

SPF 50 filters about 98% of the UV rays.

(This is calculated by 1 divided by 50 (which is the SPF number) = .02 = 2% meaning it only allows 2% in so 98% coverage) vs. SPF30 which is 97%. (1 ÷ 30) x 100 =  .03 = 3% meaning it only allows 3% in so 97% coverage)

If math is not for you, here is what you need to know: the difference between SPF 30 & SPF 50 is only 1%.

However, the difference between something like SPF 30 and SPF 2 is consequential. SPF 2 only blocks 50% of UV rays vs. the 97% you would have gotten with SPF 30. Makes sense?

In truth, 100% blockage is unlikely, your goal should be to limit the number of UV rays that can enter your skin.

Related: The Difference Between Mineral & Chemical Sunscreens

Okay, so what are your favorite sunscreens?

Favorite Mineral Sunscreens

Favorite Chemical Sunscreens

Favorite Hybrid Sunscreens

So what should I look for in my sunscreen?

You want to make sure that your sunscreen provides both UVA & UVB protection. I know I’ve mentioned these a few times, let me explain what they are. These are two different types of rays that come from the sun.

  • UVB rays are short, high-energy wavelengths that enter your skin’s top layer or the ‘dermis’. UVB rays can cause freckles, skin pigmentation, sun spots
  • UVA rays affect the DNA of your cells and go much deeper into the skin. These rays can cause skin cancer & wrinkles.

If this is too much information, just remember that UVA is for “Aging” and UVB is for “Burning” – better?

When should I use it?

Everyone including people of color needs SPF. Your sunscreen should be applied as the last step in your skincare routine before the first step in your makeup routine. Meaning that you should use it after you apply your morning moisturizer + before your makeup primer. Let it dry for 2-3 minutes before adding primer.

Related: An Expert Shares What Our Skincare Routine Order Should Be

See Also

How much do you need?

This is actually one of the most important things that I learned through my research. You need a 1/4 teaspoon of sunscreen every day.

Wait, that’s a lot. Heck yes, it is! I was shocked to learn the amount of SPF you actually need for proper protection of your skin. I used to think a few dots and I was golden – not so much.

Can’t I use foundation that already has SPF in it?

You would think so, right? But no. Well, you absolutely can and there’s no such thing as the SPF police (wait, right?) but you’re here because you want the truth so here’s the kicker.

You actually need the full 1/4 teaspoon of SPF to get the proper protection. So it’s not about the mix, it’s about the amount. Do you know how much primer or bb cream you would have to apply to get 1/4 of a teaspoon of the SPF on your face?

You likely need to double (sometimes triple) the amount of makeup foundation to actually get the coverage you need. Yuck. Use a true sunscreen to get full coverage.

Related: My Favorite No White Cast Mineral Sunscreens

Where do I need to apply it?

Face & neck every single day.

Anything else I need to know?

SPF doesn’t accumulate, so if you are wearing a moisturizer with SPF 15 and a Primer with SPF 5 that doesn’t mean you have SPF 20 on – it’s just the highest number, so in this case, 15.

To add insult to injury, SPF goes bad and should be repurchased every year. It degrades and therefore isn’t as effective over time.

SPF requires a double cleanse to remove at the end of the night (specifically on your face) – but you should be doing that anyway, right?

Related: The Art of the Double Cleanse

Final Thoughts on Why Everyone (Including People of Color) Needs SPF

I hope this helps you understand the importance of SPF & sunscreen. To me, this was always a topic that was discussed but I never knew why it was important and maybe it was my South-Asian upbringing, but tanning was always more of a concern than true skin damage.

I certainly didn’t know that I needed to wear it every day (i.e. not at the beach) and the amount blew my mind! I hope you learned something, if so, please share this with a friend!