How to Calculate Cosmetic Formulation Amounts from Percentages
Question
How do I calculate the required amount of each ingredient in a cosmetic formulation based on its percentage? For example, if I want to make 50 grams of a serum with the following formula:
- Water: 95%
- Substance A: 3%
- Substance B: 2%
How do I calculate the weight in grams for each ingredient?
Answer
Calculating the amount of an ingredient based on its percentage in a formulation is quite straightforward. The percentage tells you what proportion of the total weight of your final product should be that specific ingredient.
The basic formula is:
Ingredient Weight = (Ingredient Percentage / 100) * Total Formulation Weight
Let's use the example you shared to illustrate:
Suppose you want to make a serum with a total weight of 50 grams, and the formula is:
- Water: 95%
- Substance A: 3%
- Substance B: 2%
(Note: The percentages should add up to 100%)
Here's how you calculate the weight for each ingredient:
Water (95%):
(95 / 100) * 50 grams = 0.95 * 50 = 47.5 gramsSubstance A (3%):
(3 / 100) * 50 grams = 0.03 * 50 = 1.5 gramsSubstance B (2%):
(2 / 100) * 50 grams = 0.02 * 50 = 1.0 gram
To check your calculation, add up the weights of all ingredients:
47.5 g (Water) + 1.5 g (Substance A) + 1.0 g (Substance B) = 50 grams
This total matches the desired total weight of your serum, so the calculations are correct.
This method applies to any ingredient in your formula. Just take its percentage, divide by 100, and multiply by the total weight of the batch you want to make.