By Grams
Being able to determine the optimal and right amount of sunscreen you are slathering by the weight is another option. Some people feel more comfortable assessing things by weight. To determine the amount of sunscreen in weight, you should know that grams-to-milliliters are a one-to-one conversion, which means that the quantity of sunscreen to apply will also be 1 to 2 grams.
However, you should know that using this method may not be as straightforward as you would think. You are basing it off the weight of the product you are using in which they are either liquid, spray-on, lotion or cream, and they can all have different weight.