It is essential to measure all your ingredients by weight. In this way you can accurately calculate the percentages of each of your ingredients in your formulations. You need these weight percentages for your products’ entries in the CPNP. When you calculate accurately in one unit of measurement (grams) then you can scale up without having to do any last minute weighing or arithmetic whilst you are also making your products.
We have created this example of a lip balm recipe in order to illustrate accurately calculating each percentage.
Lip balm recipe – Using Excel to do the arithmetic
Like-for-like millilitres/grams only exists for water. That means that 100 millilitres of water is equivalent to 100 grams. Oils are lighter than water so all oils in liquid form must be weighed to give an accurate figure. For example, 100 millilitres of almond oil only weighs 92 grams. If you do not weigh your oils then you will not be able to replicate your product accurately when you scale up.
To accurately calculate the percentages:
- Weigh all of your ingredients (column D in the example above).
- Total the weight (cell D8 in the example).
- Divide the weight of the individual ingredient by the total weight of all ingredients and multiply by 100 (formula example shown for beeswax in cell E2).