Reader question: Can we add up SPF numbers?

Hi Liz! I just want to understand how the SPFs on multiple products work. If I use a facial moisturizer with SPF 15 and then layer it with a facial powder with SPF 15, does that mean that I'm wearing a total of SPF 30 on my face? I just want to make sure if my understanding is correct. If this is the case, then I can sparingly use a more expensive facial moisturizer with SPF 30 and then simply use the moisturizer-powder combination more frequently and I will have the same degree of protection either way. Thanks in advance for the clarification. - Maybelle

Hi Maybelle! Thanks for your question. I talked to a dermatologist before about this, and she said that it's not possible to layer SPF products to get a higher number. You will just get a higher volume of the sun screening ingredients, which means you get better protection, but it's still on the same SPF15 level. If you mix SPF15 with something that has SPF30 though, the higher number is the amount of protection your skin will receive.

The thing is most people don't apply enough sunscreen to actually maximize it. Dermatologists recommend at least a teaspoon of cream on your face and on each arm, and at least a tablespoon on each leg. But that's rather uncomfortable, isn't it? On the face I mean. That amount would feel quite thick, which is why a higher SPF number on the face is better than the bare minimum (which is SPF15). For example, if you have an SPF50 powder and only apply it sparingly, then you might get at least SPF25 out of it. This is just a guesstimate okay, so don't quote me on that!

Try a light SPF50 base like the Laneige Snow BB Soothing Cushion SPF50

My point is that we shouldn't scrimp on applying our SPF products. :) You can layer them together to get a more solid protection or choose one product that you feel is comfortable enough to slather on your face. I prefer to use a moisturizer with SPF OR my usual moisturizer + a makeup base with at least SPF30 in it. 

Hope this helps!