I wanted to talk more about ingredients for hair products, especially conditioner, which is very similar to lotion-making.   Before we get too deep into technical formulas, however, I want to help anyone who may not understand the basics of formulating in percentages and also grams.

This is a post that I thought should be addressed although I know many of you already know the "math".   The truth is, so many soapers have never made lotion or other products, and have only needed to use Cups or Tablespoons of ingredients.   But, we are not baking a Cake!  Haha! 

So, to be a great cosmetic formulator who can whip up any product from a simple ingredient list, I will share the procedure of converting percentages to grams, etc..   I will TRY to keep it very simple as I hate math more than most, so I understand the urge to turn and RUN!


Before I start I highly suggest that you get a notebook.  You probably have one full of recipes and if so that is great.   We will need, however, this simple guide to which you can ALWAYS refer back, when making those formulas. 

I am not a math teacher and I know everyone has their own "way" to do things, but..  if you do not have a way to do this equation yet, I will give you my technique and you can opt to use it if you like.  If it works, I suggest keeping it in the front of your recipe book.  


To start, I will point out that many people DO NOT know how to do this and just plug numbers into a "Lotion Calculator", which can be very accurate.  I do not use that program but have heard no one complain about it (although it usually is set up for specific emulsifiers and maybe not the one you want to use). 

Also, sometimes we want to make something that is NOT lotion but still need to know how many grams is 3% of wax, etc..

This is the long version.  If you would like to see these rules written without the explanation, just scroll down to "QUICK SUMMARY" .


So, let's begin...

The word problem.  

You may remember this from school.  Any time you see the word "of" in text (regarding math or formulating) you always MULTIPLY.   The word "is" always means equal sign/ equals.


How do we work with that darn percent sign?


Follow this rule EVERY TIME.  Once you are using the percentage in the math problem you MUST drop that pesky symbol at the end...  BUT you cannot just drop it.  You MUST turn it to a decimal point and move that decimal point two places to the left.  Every time.  No exceptions.  You cannot add, subtract, multiply, divide or do any math to a number with a percent symbol at the end.   You MUST turn it to a decimal and move it TWO places to the left.  It is the same thing as the original number with the symbol..   You have simply converted it into a "workable" number.


50% of 100 is ?  

Drop that percent sign and make it a decimal.  Move it two places to the left.  The new equation now says:

.50x100 =50    And it makes sense right?  Fifty percent of 100 is 50...   (half)  Half of fifty is fifty.


2% of 100 is?

Bye-Bye Percent sign!  Make a decimal point and move it two places to the left.  The new equation now says:

.02 x 100 =2  Think about it in your head..    Two percent of 100 is 2.  



It is OK to use the online Calculator!     (I highly recommend it actually.)


So, how do we figure out the ounces and grams and connect it all together?

The very first thing you have to do is decide how much product you are making.   This is more difficult than it sounds.   If you are making lip balm for you and family you may only want to make twenty tubes (.15oz each).  If you are making to sell, you may want to make over 100 tubes (.15oz each).   If you are trying a lotion formula for the first time you may want to start with 12 -16 oz...  If you are making a batch of "tried and true" lotion to sell you may be  filling 100 eight oz bottles.

So, get your total batch amount set before you do anything.


Bottles and containers are almost always sold in ounces but experienced cosmetic formulators always suggest using grams.   So, take your total batch amount in ounces, and convert it to grams.  I highly suggest using the conversion tool supplied in your Google search engine.

So I want to make 50 lip balms -each is .15oz.   (50 tubes OF .15 ounces lip balm IS)

I need to multiply 50x.15 to see how many total ounces I have.   The answer here is 7.5 total Ounces.  Now we Google: "Convert 7.5oz to grams"...  and that answer is our total gram weight for the entire formula.  The answer given is:  212.62 Grams.  You can round up or down if you desire but some formulas require very specific measurements, so try to keep it as close to the actual number as possible.


Do this for every ingredient.   


2% Castor oil will be .02 Castor oil..   Drop that pesky percent symbol and turn it to a decimal point.  Remember you move two spaces to the left and if there are NOT two spaces you use a zero as a place holder.  This never changes in math.

25% Shea butter will be .25 Shea butter. 

1% Vitamin E will be .01 Vitamin E.



And since EVERY INGREDIENT is part of (multiply) the "whole" batch, -we multiply each ingredient's percent (in decimal form) to the ENTIRE BATCH WEIGHT...  This is why we need to know the total batch weight we are creating at the very beginning!


.25 (Shea) of total weight is how many grams?  .25 x 212 grams (for an example of a total batch weight)=53 grams.


Remember we converted our total formula from ounces to grams at the very beginning.  Now we just use our calculator.


Do this for each ingredient prior to mixing or heating ANYTHING.    This is your formula you will follow and share if you need help.  It will have the gram weight AND the percentages for those to duplicate without having to make 100 bottles of anything.   (Because the formula never changes once it is in percent form!)

Then each percent is converted to a weight using your calculator. 


So 12% ingredient A of total batch weight is what number...?   It is .12 x total batch wgt in Grams               (.12 multiplied by total ounces -converted to grams at the beginning of the formula).  

This is now Ingredient A in grams, to be added to your product.



1.  Decide how much product you are making.  Take one container and multiply it's capacity (usually in ozs) by the total number of containers you will be using.  This is your total batch weight in ounces.   You will be converting this number to grams next.

2.  Convert that number to grams.  This is the total batch weight YOU WILL USE.

3.  Take every ingredient listed as a percent, and turn each number to a decimal (explained above), -Then multiply that number with your total batch weight (in grams).  This will be each ingredients individual gram weight.

HINT:    If you add all these weights together you should get a number very close to, if not identical, to your total batch weight.  In turn, if you add each ingredient-percentage, the total should always add up to 100%.




Try to learn this if you can, as Cups and Tsp are never used by advanced formulators.   Also,  if someone had a formula in percentages, you would want to know you can make it yourself!  If you do not know how to turn percents to decimals, and convert ounces to grams, you will have a tougher time than necessary.

And, do not underestimate PRACTICE.   Do some of these problems on paper and in discussion with others...   Once it "clicks" you will understand it EVERY TIME.   


If anyone has anything to add to this, or if this helped anyone who is trying to understand "the math behind the Science", please leave a comment.   So many people feel alone and yet it is a HUGE issue for many.  Never be embarrassed for asking questions!  It is those who do not ask questions that make inferior, -or even dangerous products.


I hope this was helpful to everyone and if you'd like to share a thought on today's post, please comment below! 

Thank you for visiting Rae Jean's Blog at Soaper's Supplies, and check out our new SEARCH bar on the home page to help tour the ingredient list!



RJ's Skincare Blog and any included recipes are researched and written by Angela D'Amico.

Write a comment

Comments: 4
  • #1

    Rae Wycoff (Sunday, 17 July 2016 16:24)

    Awesome, Angela! Thanks!!!

  • #2

    Arnette Theiss (Thursday, 02 February 2017 18:47)

    You need to take part in a contest for one of the greatest websites on the internet. I most certainly will highly recommend this web site!

  • #3

    Linda Wollman (Friday, 03 February 2017 01:17)

    Hurrah, that's what I was searching for, what a stuff! existing here at this blog, thanks admin of this site.

  • #4

    Beth (Monday, 06 March 2017 23:24)

    Good job! I am sure you helped many potential formulators.

    Do you know if a lotion calculator? I cannot find one online.

    Thank you.