What Level of SPF Do I Need?
Summer is here, and that means tons of activities outdoors. This also means coming into contact with the sun. Protecting yourself from the sun’s harmful rays is vital to your health. The most popular way of doing this is with sunscreen. But once you go to the store to buy some sunscreen, all the different SPF levels overwhelm you. You might be asking yourself: What level of SPF do I need? What is the difference between all these levels? Which one is best for me?
SPF 101
First, let’s go over what SPF means. SPF stands for “sun protection factor.” The SPF level measures the amount of protection the sunscreen offers from UVB rays, which cause sunburn and contribute to skin cancer. There is some math involved to figure out which SPF level you should consider.
If your skin normally burns within 10 minutes of being in the sun, an SPF 15 sunscreen would theoretically let you be in the sun without burning for about 150 minutes. So multiply your burn rate (10 minutes) by the SPF level (15) to get your protection rate (150 minutes). In other words, if you use SPF 15, it takes 15 times longer to burn than if you didn’t have any sunscreen.
Keep in mind this is not a guaranteed protection rate; sunscreen wears off after two hours, so staying in the sun for 150 minutes or more is not a good idea. SPF should not be used to consider how long to stay in the sun without reapplying sunscreen.
Also, SPF does not measure the protection rate against UVA rays, which deeply penetrates the skin and can cause aging and potentially skin cancer. To try and protect against both UVB and UVA rays, look for a sunscreen that says “broad-spectrum” or “UVB/UVA protection.”
So What Level of SPF Do I Need?
Typically, you want to go with the level of SPF that best corresponds with your skin. Again, this is not a guarantee, but it is a general rule of thumb.
Darker skin can usually do well with SPF 15 since there is more melanin present in the skin. Melanin, fortunately, does offer some protection. SPF 30 is the more common level and is recommended for everyone. Next is SPF 50 and SPF 100 is the highest level. Based on how fair your skin is, you might want to consider SPF 50 or 100.
You could also look at it this way: SPF 15 blocks about 93% of UVB, SPF 30 blocks about 97%, SPF 50 blocks about 98% and SPF 100 blocks about 99%. So even though there is no guaranteed 100% protection, you can try and get the most protection available. You should also factor in how much time you are going to spend in the sun and the altitude. Places with higher altitudes can have increased levels of UVB rays. If you are planning a full day at the beach without any shade, definitely consider SPF 50 or 100.
Protect Yourself at All Costs
Now, just because you use SPF 100 does not mean you are invincible to the sun’s rays. Don’t forget to reapply the sunscreen every two hours. Help protect your skin with hats, umbrellas and anything else that can offer shade. Avoid peak UV hours between 10 a.m. and 4 p.m.
If you are going to the beach or somewhere with water, make sure your sunscreen is water-resistant. Otherwise, it will wash off as soon as you get wet, which defeats the purpose. You should reapply the sunscreen immediately after swimming or sweating, even if you put some on right before.
Also, be honest with yourself – if you know that you are prone to skipping or not applying enough sunscreen as you should, go with a higher level SPF to give that little boost of protection that can make all the difference between you and a bright red lobster.
If you have any questions regarding sunscreen and SPF, check out the FAQ at the American Academy of Dermatology.