We all know the traditional sunscreen rules: wait 15 minutes before sun exposure, reapply after two hours, hit your hands/neck/ears/webs of fingers and toes, blah, blah, blah. The word “should” in the question of how much sunscreen should one be using complicates things, according to Dr. Christina Lee Chung, board-certified dermatologist at Schweiger Dermatology Group in Philadelphia, PA. “Technically, to achieve the SPF listed on the product, you need to apply 2mg for every 1cm of your body, which is a significant amount of sunscreen,” she explains. “Realistically, you should apply a good coating to exposed areas daily, with reapplication every two hours to ensure maximal sun protection.” You may have heard of the ‘two-finger method,’ where you measure two fingers worth of sunscreen to your index and middle fingers and apply to your face.
