Formula Percentages

Hey All!

I've been working on a natural deodorant formula for the past two months.  However I was measuring everything in teaspoons and my formula percentages were based on teaspoons.  I am now working in a more detailed fashion and bought a lab scale.  I've converted my formula into grams by converting the weight of a teaspoon of a given ingredient into grams.  

I weighed all ingredients before I started any of the phases for creating the deodorant.  Meaning my waxes, butters, and oils were in their original state.  Should I convert my solids to liquids and then weigh? Or does it not matter?  How do folks typically create the percentages in their formulas here?

Much thanks,



  • PerryPerry Administrator, Professional Chemist
    No need to convert solids to liquids. Mass (at least when you're not moving close to the speed of light) is constant.

    Weigh all your ingredients. Add up the weight. Then divide the Amount of Ingredient by the amount of all ingredients to get the relative percentages.

    All the percentages added together should equal 100%
  • Thanks, Perry! This is very helpful!
  • @Perry I have a question and would be grateful if you could answer to me. I use a lab scale and weight all my ingredients. 
    when I have to weight a preservative, for example phenoxyethanol, and want to use it in 0,9% in a total amound of 100 grams,do I have to weight 0,9 grams of phenoxyethanol?
    Or because it is liquid, do I have to consider it's desnity?

  • PerryPerry Administrator, Professional Chemist
    You only have to weigh the amount of phenoxyethanol. So, weigh 0.9 grams.

    You only have to consider density when you are measuring in terms of volume. Using a scale is measuring in terms of mass.
  • .9g is correct. We use mass % so that density isn't a factor. As a new lab tech I get tripped up sometimes because I will begin to build a phase in too small a beaker because I generally assume that 1g=1ml; because of differing densities I sometimes run out of room. You would only consider density if you were using volume measurements.
  • thank you so much @Perry and @Bubbles
    much appreciated comments, I am always afraid if I overdose or underdose a formula. 
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