Calculating Ingredient Percentages in Cosmetic Formulation
Question
When formulating cosmetics, should ingredient percentages be calculated by weight or volume? How do I calculate the amount of each ingredient needed based on the percentage and the total batch size?
Answer
Subject: Calculating Percentages for Cosmetic Formulation
Hello!
It's great you're interested in making your own cosmetics. Understanding percentages is key!
In cosmetic formulation, percentages are almost always calculated by weight (grams), not volume (milliliters). This is because measuring by weight is much more accurate and consistent for different ingredients.
Here's how the calculation works:
- Determine your total batch size: Decide how much product you want to make in total (e.g., 100 grams, 50 grams).
- The total batch size is 100%: Whatever your total batch size is in grams, that amount represents 100% of your formulation.
- Calculate ingredient weight: If an ingredient is listed at X%, the amount you need is (X / 100) * Total Batch Size (in grams).
Example:
- If you want to make 100 grams of cream and an ingredient is used at 5%:
- Amount needed = (5 / 100) * 100 grams = 5 grams.
- If you want to make 50 grams of cream and the same ingredient is used at 5%:
- Amount needed = (5 / 100) * 50 grams = 2.5 grams.
Always use a scale to weigh your ingredients accurately.
Starting with small batch sizes (like 50g or 100g) is a good way to practice and minimize waste.
Hope this helps clarify the percentage calculation! Feel free to ask if you have more questions.