Calculating Ingredient Percentage in Formulation
Question
How to calculate the amount of an ingredient needed for a formulation based on its percentage concentration, specifically how to interpret percentages like "Alpha Arbutin 2%" and scale the amount for different batch sizes (e.g., 50 grams)?
Answer
Percentage in formulation usually means weight per volume or, commonly, weight per weight (g/g). For example, 3% of an ingredient means 3 grams of that ingredient in 100 grams of the total formulation (the final product).
To calculate the amount needed for a different total weight, you can use the rule of three.
Example:
If you want to make 50 grams of a product containing 3% of an ingredient, you would calculate:
(3 grams / 100 grams) * 50 grams = 1.5 grams of the ingredient
So, if you want to make 50 grams of product and need 3% of that ingredient, you would weigh out 1.5 grams of the ingredient.