Fragrance oil usage rate

Fragrance oil usage rate is the maximum percentage of a fragrance oil that its supplier or manufacturer publishes for a particular application, such as cold process soap, melt and pour, or lotion. It is based on the fragrance's ingredients and is usually listed on the product page or a linked data sheet as a percentage of the total oil weight.

Usage rates exist because fragrance oils are concentrated blends, and some ingredients within them are recommended only up to a certain level in a leave-on or rinse-off product. Rates vary a lot from one fragrance to another, and even between different suppliers selling what sounds like the same scent, so a rate cannot be assumed to carry over.

When formulating, calculate the fragrance amount as a percentage of the oils in the recipe, not the total batch weight including lye water, since that changes the math. A common mistake is using a rate from one supplier's fragrance on a similarly named fragrance from a different supplier, or increasing the amount because a scent seems faint before the bar has cured.