How Much Fragrance Oil Per Pound of Soap?

By Marsha Harrison

Fact-checked by Kia Lowe

how much fragrance oil per pound of soap

The art of scenting soap is a work filled with power, nostalgia, and accuracy. In a world of soapmakers, the scent they embedded must be retained and infused until to its very last pound.

So, how much fragrance oil per pound of soap do you need? In general, one pound of soap requires about 0.8 ounces of oil to create a strong aroma. And for every pound of soap, it equates to about two teaspoons of fragrance oil.

Continue reading as we endeavor the world of soapmakers.


Steps to Determine the Fragrance Oil Amount Per Pounnd of Soap


Step 1: Determine the process for your soap making.

Knowing the process you will utilize in making soap is important because different methods require different measurements.

And since the time of the Roman legend about Mount Sapo, soap-making has undoubtedly advanced significantly. Today, these are the 4 most common methods of making a soap:

  • Cold Process

If you ever caught yourself staring at a bar of soap due to its immense beauty of colors and swirls, it is highly probable that it is made from a cold process.

This method is inexpensive and basic and only requires mixing water, lye (strong alkali), and oils. After putting it in a mold, saponification, a chemical reaction that transforms oil into soap by alkali activity will occur.

For saponification to start, the dose of fragrance oil added to the cold process soap must be precise. In this technique, o.6 – 07 ounces (20g) of fragrance oil is recommended for every pound (454g) of soap.

  • Hot Process

The process of saponifcation also happens in this technique. Still, from the word itself, the hot process has an added heat that speeds up the action.

The amount of fragrance oil to add to hot process soap is 0.25-0.35 ounces (7-10g) per pound (454g) of soap. Important reminder to not mix the fragrance oil when the soap is still scorching hot as it will evaporate and lose its aroma.

  • Melt and Pour

Another easy yet wonderful way of creating soap is by Melt and Pour. Since this method uses a commercially formulated soap to be melted and already gone through the saponification process, you will only need your personal chunks of decorations.

The recommended amount of fragrance oil to add to melt and pour soap is a maximum of 0.5 ounces (14g) for every pound (454g) of soap. The precise amount may still change depending on the fragrance oil you choose (to be discussed later).

  • Hand-Milled/Rebatch

Lastly, Hand-milled/Rebatch is a method that shreds any soap into smaller pieces to correct/improve ingredients. And if you want some fun, adding oils, herbs, and colors will do!

For this process, 0.4 ounces (11g) per pound (454g) of fragrance soap will be enough to make the scent long-lasting.

In a nutshell, soaps used in the cold and hot process are made from scratch. As a result, accurate measurements must be considered for saponification to happen.

Meanwhile, soaps used in melt and pour, and rebatch are ready to be mixed with desired oils and decors so the amount can be adjusted without affecting too much of the process.

Step 2: Identify the type and strength of oil you will use.


The fundamental distinction between fragrance oils and essential oils is that the former is produced in a lab synthetically. Meanwhile, the latter are created from natural ingredients.

In comparison, the dose of fragrance oil and essential oil to add to soap doesn’t make much difference. Such 0.3 ounces of fragrance oil to add to melt and pour soap per pound is the same amount (0.3oz) for the essential oil per pound of soap.

But what matters in this conversation is the strength of the oil scent you use. To demonstrate, a maximum of 0.2oz per pound of soap base would be sufficient for Cherry Almond which possesses a slightly strong scent.

Be careful not to put too much fragrance oil in soap as it can result in an unpleasant smell, dermatitis, and waste of resources.

Step 3: Familiarize with Fragrance Oil Blending Chart for Soap.


Creating perfect scent notes can be more exciting when combined magnificently. The blending chart is a handy tool to check for the blend-ability of different types of scents, as well as how many drops you can add in a safe amount.

The International Fragrance Association (IFRA) is an organization on a global scale that assures product usage of a safe amount of fragrance oil. Accordingly, essential oil to add to soap has a safe usage rate of 3% or no more than 3g per 100g of soap.

Additional Tips for Soap Making


1. Use a Fragrance Calculator For Soap

This simple strategy of estimating the dose of fragrance oil to add to soap is just by the end of your fingertips. One-minute internet surfing might be the solution to your math agony.

2. Always wear gloves when measuring fragrance oils.

Your safety should not be compromised when perfecting your signature soap scent. Protect your hands when handling a strong alkali such as lye and a very concentrated form of fragrance oil. Exposure to these can cause irritation and allergy.


One of the fascinating aspects of creating your own soap is choosing the fragrance. And once you are swept into a whirlwind of memories that the fragrance notes bring, you might be unstoppable in making a bar of soap.

Given the complexity of making soap, from determining the process, and identifyaing the fragrance oil to familiarizing yourself with the blending chart, we hope this article enlightened you on how much fragrance oil per pound of soap you need. In fact, we hope that we have moved you one step closer to mastering the art of scenting soap.

Happy Soapmaking!

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