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How to Stop Guessing at the Essential Oil Usage Rate When You Make Soap

Now that I’ve dished on my top ten recommended essential oils for soapmaking, I want to dig into the age old question of:

How do I figure out the usage rate of XYZ essential oil? How much essential oil do I use in soapmaking?

Unfortunately, this is never a straightforward answer, but let’s decipher the in’s and out’s of essential oil usage rates in soapmaking!

Essential Oil amount to use in soap

Converting your essential oil usage rates from percentage to weight

For most cosmetics formulating, fragrances are used at a rate of 0.5% to 5% of the total formula: less for leave-on products, more for wash-off products, and even more for non-skin contact products.

As cold process soap is a wash-off product, the standard essential oil usage rate falls in the mid-range. I generally use an essential oil usage rate of 2% to 4% of my soaping oils.

For example, if your soap mold holds roughly 4 oz of oil per cavity (giving you 4.75 oz bars of soap), a 3% usage rate would be found like so:

4 oz x 0.03 (3%) = 0.12 ounces or roughly 3.5 grams of essential oil

Notice how the essential oil usage rate is calculated from the oil of the formula, and not from the total. Why is that? In soapmaking, we use water (or other liquids) as a carrier for the sodium hydroxide (lye) to complete saponification. After saponification is complete, the water mostly evaporates from the formula during cure. If you calculate your essential oil usage rate based on the total formula, it will become more concentrated during cure – not good!

As a side note: I have never used drops for anything as they are highly inaccurate and vary so widely (big drops, little drops, oops, an extra drop, etc.). I always weigh my ingredients, including my essential oils, in soapmaking – no drop, cups, or guessing!

Where this gets complicated with essential oil usage rates is that each individual essential oil poses its own unique challenges, guidelines and needs, due to possible skin irritation, sensitization, photosensitivity, and performance in soapmaking. Some essential oils have a lower recommended usage rate than others due to these issues.

Personal preference plays a part in deciding how much essential oil to use

Here are my personal maximum essential oil usage rate guidelines for soapmaking:

Essential Oil Per Pound of Oils Percentage of Oils
Amyris 0.40 ounces PPO 2.50%
Anise 0.15 ounces PPO 0.94%
Basil (Sweet) 0.30 ounces PPO 1.88%
Bergamot (Bergaptene Free) 0.70 ounces PPO 4.38%
Black Pepper 0.08 ounces PPO 0.50%
Cedarwood 0.50 ounces PPO 3.13%
Cinnamon Leaf 0.08 ounces PPO 0.50%
Citronella 0.50 ounces PPO 3.13%
Clary Sage 0.50 ounces PPO 3.13%
Clove Bud 0.08 ounces PPO 0.50%
Eucalyptus (Globulus) 0.50 ounces PPO 3.13%
Fir 0.70 ounces PPO 4.38%
Geranium 0.50 ounces PPO 3.13%
Ginger 0.30 ounces PPO 1.88%
Grapefruit (Cold Pressed) 0.80 ounces PPO 5.00%
Lavender 40/42 0.80 ounces PPO 5.00%
Lemon (Cold Pressed) 0.80 ounces PPO 5.00%
Lemongrass 0.80 ounces PPO 5.00%
Lime (Cold Pressed) 0.80 ounces PPO 5.00%
Litsea Cubeba 0.70 ounces PPO 4.38%
Orange (Sweet) 0.80 ounces PPO 5.00%
Orange (Folded) 0.50 ounces PPO 3.13%
Palmarosa 0.40 ounces PPO 2.50%
Patchouli 0.50 ounces PPO 3.13%
Peppermint 0.40 ounces PPO 2.50%
Peru Balsam (Distilled) 0.15 ounces PPO 0.94%
Petitgrain 0.50 ounces PPO 3.13%
Pine 0.40 ounces PPO 2.50%
Rosemary 0.50 ounces PPO 3.13%
Spearmint 0.30 ounces PPO 1.88%
Tea Tree 0.50 ounces PPO 3.13%
Vetiver 0.30 ounces PPO 1.88%
Ylang Ylang (Complete) 0.40 ounces PPO 2.50%

If you want to use an essential oil with a low usage rate, you can pair it with essential oils that have a higher usage rates. For example, creating a blend containing clove bud essential oil and patchouli essential oil together, which gives you a total of 0.58 ounces maximum (0.5 oz ppo patchouli, 0.08 oz ppo clove.) Your combined essential oil usage rate (the total sum of all essential oils) should not reach over 0.8 ounce to 1 ounce per pound of oils (5% to 6.25% of the oils.)

Each of these maximum essential oil usage rates for soapmaking were pulled from my personal reference sheet, calculated based on experience, strength of scent, and standards compliance. I prefer my products scented in a mild to moderate amount, so you may choose to use a higher essential oil usage rate based on your preference.

I briefly checked each essential oil usage rate against current IFRA Standards (48th Amendment) using my personal stock of essential oils and their specific information to the best of my ability. (I’m not perfect and will add any corrections as necessary, please continue reading to learn how to check the standards yourself!)

Wait, what are IFRA Standards?

Yessum, there is yet another layer to calculating your essential oil usage rate! The International Fragrance Association (IFRA) Standards work to regulate the safe use of fragrance materials that are skin sensitizers and irritants.

The International Fragrance Association establishes guidelines for safe usage, and works with the Research Institute for Fragrance Materials (RIFM) to determine these guidelines based on scientific analysis rather than unconfirmed reporting or speculation.

This is starting to sound complicated, right? To make safe essential oil usage rate info more accessible to to the soapmaking community, I’ve created the EOCalc. With this tool, you can calculate safe usage rate for your own essential oil blends or you can explore fragrance blends from my personal formulary and submissions from our tribe. Check out everything to EOCalc can do for you!

Compliance with the IFRA standard are on a volunteer basis but are recommended. While membership of the IFRA is usually out of reach for white cottage manufacturers (such as you and I), the standards and practices recommended by the IFRA are open for public viewing and understanding.

The IFRA Code of Practice and the IFRA Standards Booklet are available on IFRA’s website: http://www.ifraorg.org

Three IFRA Standards classifications effect essential oil usage rates

  • Prohibited means that you should not use the ingredient at all.
  • Restricted means that you can use the ingredient, however, it should only be used below a certain concentration level.
  • Specification means that you should evaluate purity criteria.

IFRA Product Categories also determine essential oil usage rates

And there are eleven categories of product types that are used to determine safe usage rates, they are as follows:

  • Category 1: Lip Products, such as lipstick, lip balm, lip scrubs
  • Category 2: Deodorant and antiperspirants
  • Category 3: Hydro-alcoholics for Shaved Skin, which include eye products, men’s facial care products, and products for children or infants
  • Category 4: Hydro-alcoholics for Unshaved Skin, which include some hair products, body mists, body lotions, body oils, foot care products, and fragrance ingredients in cosmetics and perfumery kits
  • Category 5: Facial care products, facial masks, hand cream products, dry shampoo, and permanent hair products
  • Category 6: Mouthwash, toothpaste, or sprays
  • Category 7: Insect Repellents
  • Category 8: Makeup remover, hair styling aids, nail care products, and any powder or talc products
  • Category 9: Wash-off products such as soap, bath gels, body washes, shampoo, conditioner, liquid soap, or shaving cream
  • Category 10: Laundry detergent, fabric softener, and household cleaning products
  • Category 11: Non-skin contact products that may come in contact with skin, such as air fresheners, candles, and reed diffusers

Before using any essential oil in any product formulation, you should check the IFRA Standards for compliance on usage rates in specific product types. Unfortunately, this is becoming more difficult for the less knowledgeable formulator as many of the standards have shifted to listing by specific constituent rather than the complete essential oil. (That’s why I created the EOCalc to help soapmakers at every level.)

For example, cinnamon leaf essential oil is a restricted material due to its eugenol content. In order to comply with the IFRA Standards, you must know the eugenol content of your cinnamon leaf essential oil to determine the safe usage rate in your product category (if it’s soap, that’s category 9 and the max eugenol content is 0.5% currently). The eugenol content of your essential oil can be found on either a CoA, (M)SDS or GC Analysis of the essential oil from your supplier, and it can vary from batch to batch and crop to crop.

It’s important to note that each individual batch and crop of an essential oil can contain differing levels of constituents, so you will need to check your specific essential oil. For example, New Directions Aromatics currently lists their cinnamon leaf essential oil as 82.8% eugenol, but the cinnamon leaf essential oil I currently have on hand contains 77.2% eugenol. Because eugenol is the restricted material and not the whole essential oil itself, your maximum usage rate will be slightly different than mine.

For the EOCalc, each essential oil profile was created from a sample of actual GC/MS analyses performed on essential oils that have entered the marketplace, GC/MS analyses from scientific literature and studies, and reputable research sources, such as Tisserand’s Essential Oil Safety. For more details, check out the EOCalc’s Frequently Asked Questions page.

Now, you wouldn’t want to use more than 0.5% of cinnamon essential oil in cold process soap anyways, as more than that will accelerate your soap beyond most reasonable amounts for a soapmaker!

Thankfully, great essential oil suppliers are extremely knowledgeable about the products they sell in regards to restrictions and can usually answer any questions you may have. Many even list standards compliant essential oil usage rates on their website, so you can skip the math!

Want to learn everything about using essential oils in soap and cosmetic in one place? Grab a copy of my book Smellgoods: How to Use & Blend Essential Oils in Handmade Soap & Skincare.

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66 Responses

    1. Thanks for stopping in, Joan, and for contributing to the series! I’m sure folks will love trying out your top ten recommended essential oils. 🙂

      1. What do you recommend as a usually rate for Cocoa Absolute, Coffee Bean CO2 extract (organic), and Vanille (vanilla replacement with essential oils and vanilla absolute). I can’t seem to find this information anywhere! I’m trying to go more “natural” in scent for my CO soaps. Thank you and I love all your information!

        1. Hi Amanda

          I am trying to do a blend of the same oils for my coffee and chocolate CP soaps. I am considering ‘sweetening’ the blend with ylang ylang or may chang. Have you tried this? I have found that my coffee/chocolate/vanilla blends smell a bit ‘bitter’ or ‘smoky’. Did you come up with a blend in the end? If so, I would be grateful if you could share it. I am still working on it and will be happy to share if I finally manage to blend a mix I like.

    2. This was very helpful, thank you! I don’t sell soap, I just make it for my family and friends, so I needed something detailed like this in order to formulate my own casual rule for essential oils. Now that I’ve digested this, I figure that for my normal 26 oz batch of soap I can simply combine essential oils in a pleasing way until I get to about .9 oz and I’m good to go!

  1. I would like to get a copy of the chart listed above with essential oils usage rates. How do I get one?? I have things like this laminated and in a book, saves so much time.

    1. Hi Laura! You can print the post by using the print button in the social sharing section. 🙂 It will allow you to keep the formatting properly! Thanks for reading!

  2. Hi Kenna – very useful info. However, in your blend example you have used clove (very low concentration) and patchouli (moderate concentration) which together still fall under 5% (0.5% + 3.13% = 3.63%) but in theory, if you’re making a complex blend or using two high usage oils should you divide the percentage of each according to the percentage used in the blend?
    e.g. 50:50 lavender & eucalyptus simply added would be 5% + 3.13% = 8.13% – too high. So I’m thinking 50% of each makes 2.5% + 1.56% = 4.06%
    Or – 75:25 lavender & eucalyptus = 3.75% (5*0.75) + 0.78% (3.13*0.25) = 4.53%
    Sorry, I’m a bit of a maths nut 🙂

    1. Hi Alex 🙂

      Yes, you can divide the percentage according to the blend, if you wish. The usage rates are simply maximum amounts/guidelines for me. 🙂 Hope that helps!


      1. Hi Mac, if you’re referring to my comment I gave two separate examples. First example of 50:50 calculating 50% each and second example of 75:25 calculating 75% & 25%. I hope that makes sense.

  3. Hi Kenna,
    Thank you so much for this great article and the handy chart. I will print it off as I know that I will be referring to it often. I’ve been having a terribly difficult time finding information on essential oil usage rates for leave on products. I’ve gone through the IFRA website until I’m blurry eyed and can’t seem to find anything specific. Am I missing something? Am I just dense and don’t understand the IFRA site? I would appreciate any guidance you could offer. It’s holding up an important project. Thanks so much!

  4. Kenna, this list is great. Is there another list somewhere with more EO’s on it? I cannot understand the IFRA website either. Do I need Tisserand’s book?

  5. Thank you for taking the time to put this information in a nice easy to reference form! Much appreciated.

  6. Hi Kenna, thanks so much for this great info! I know there’s quite a ton of info out there and it seems the more I research the more confused I am! Just for instance……you list spearmint as a 1.88% rate which is very low and then I see soap queens recipe for a spearmint cold process bar with a 5.8% usage rate. I know you state that these are your personal usage rates but is the usage rate window that wide? I notice that many of her recipes are high on the percentage rate with fragrances but I also noticed that her fragrance calculator includes the water and lye which is something you say not to do. I value your opinion and Ann Marie’s so I’m totally confused! I’m coming to the conclusion that there’s no right answer to any soap making question and the answers are all over the map! Help!!!!

    1. Spearmint contains a high level of carvone, which is restricted in usage by the IFRA, which influences the usage rate. I personally also scent at a lower strength that Anne-Marie across the board from what I’ve noticed, but that’s entirely personal.

      As to whether or not that usage falls within the IFRA guidelines, I couldn’t say without knowing what spearmint she is using, but carvone in soap is limited to 5%. Most spearmint has a carvone percentage in the 60% to 80% range. So, it looks like it is likely used at the high end of the max usage rate in accordance with IFRA standards.

      Everyone appreciates different levels of scent and has a different nose. Anne-Marie and I are not right or wrong, it’s simply personal preference. As long as your usage falls within safe guidelines, I think you are fine.

    2. As for including lye and water, I explained why I don’t up there. 🙂 Again, as long as the end result is the same (formulating for safe usage according to guidelines), it doesn’t matter how you get there. I don’t include the water because 85% of it evaporates and it’s easier to see what my end usage rate is without calculating it. That’s all 🙂

      1. Thanks so much for the quick reply Kenna! I find myself going to your site quite often and Anne Marie’s. I’m going to use your guideline above as a start and experiment from there for my personal preference. Thanks again!

  7. Let’s look at Lavender. You state it can be used at .8 ounces per pound of oils OR 5% of oils. If my recipe contains 6 pounds of oils X .8 ounces ppo would give me 4.8 ounces of Lavender. BUT if I use 5% of oils, I get a usage rate of .3 ounces! A HUGE difference! What am I doing wrong?!

    1. Cere, I’m not sure what second number you were getting, but this is accurate:

      6 lbs x 0.8 oz PPO = 4.8 ounces
      6 lbs = 6 lbs x 16 oz = 96 ounces x 0.05 (5%) = 4.8 ounces

  8. Hi Kenna! I’m making a cp soap in a mold shape that will be popular for kids. Do you have any suggestions regarding usage rates? I’m planning to use Lavender 40/42, Lemon, Litsea, and Orange. I’m curious whether you let the kids use soaps with EOs and what your experience has been with them. Thanks

  9. Thank you so much for posting this chart. I am very new to soap making and like others seem to be going round in circles trying to find out the legal amounts of EO I can use in soaps that I wish to eventually sell. (that is a long way off yet i am still experimenting!).

  10. Hello,

    I make lotions and I would prefer to measure my essential oils by weight instead of volume or drops. Could similar rules that you have laid out be used for lotions, lip balms, etc.

  11. What do you recommend as a usually rate for Cocoa Absolute, Coffee Bean CO2 extract (organic), and Vanille (vanilla replacement with essential oils and vanilla absolute). I can’t seem to find this information anywhere! I’m trying to go more “natural” in scent for my CO soaps. Thank you and I love all your information!

  12. Dear Kenna,

    Thank you for your taking time to write the article on the usage of essential oil. Since I m using melt and pour soap base and i won’t know the PPO it contains in the soap how do I use the formulae?

    Thank you in advance for your reply.

    Happy new year and may you have a successful year ahead !Xx


  13. dear kenna
    i am trying to find out what the % rate ppo is for sandalwood essential oil – i am having no luck at all – brambleberry cant help me – i have asked my supplier but she seems unable to help me as well – she has been helpful with everything else so far but this one i cant find out about – and i love sandalwood – i am trying to get away from FO’s – mainly because most of them smell so fake to me – just personal preference i guess – i have tried to understand the ifra site but it goes over my head – i hope you can help me

    1. Hi Liz, I’m in the middle of using sandalwood in a blend and I was looking out for help too and I found your question.. Have you been able to find a usage rate? Also, Kenna mentions that Amyris can be used as a substitute for sandalwood.. So was wondering if we could use the usage rate of Amyris instead… Any help is appreciated… Thank you

      1. Hi Surya – I still havent found and answer to this sandalwood percentage issue – I have been told that when you are not sure just use 2% – I would like a more accurate answer than that though – Have you had any luck Surya??? and Kenna I would love to get any help possible from you as well – Thank you – Liz

        1. Liz, if your supplier can’t tell you a usage rate, you will have to go through the process that Kenna did with cinnamon leaf essential oil in this article.

          You can also support and make recommendations for new oils to be added to our EOCalc, so it can do the math for you.

  14. Hi Kenna,
    I love just about everything you post. Thank you for sharing this post. I’m new to soaping, and it’s difficult to understand how much fragrance to use. It’s my preference to only use essential oils, and not any lab made fragrances. I want to keep my soap as natural as I can. I see very different opinions on how to mix and use fragrances. This was easy to understand, and makes me feel more comfortable knowing how much can be safely added. 🙂

  15. Hi Kenna,
    Thank you so much for this detailed article and the informative chart. I like to print it as guide. I’ve been having difficult time finding information about essential oil usage rates.
    Thank you

  16. Late to the party, I know. I like the variety of EO usage rates on this chart, but there’s a big one that’s missing IMO. Rose absolute and/or rose otto. Stuff is insanely expensive but I want to make at least one batch of (probably glycerin) soap scented with rose. Have you got any idea about usage rate for undiluted absolute or otto?

  17. thanks so much for this guide – i am having trouble finding out the percentage rate for both sandalwood and vanilla – i would appreciate any help you can give me – thanks

  18. Can you recommend a company I should buy my oils from. I’ve bought from stores that I thought would have good oils but it seems like I have to use a full bottle in my coconut lotions to get any smell at all.

  19. Hi, thank you for all this work and sharing.

    Could you tell me why your personal maximum essential oil usage rate in soap for Cinnamon leaf is not 0,05% like the IFRA standard for Cinnamic aldhedyde found in Cinnamon leaf essential oil?

    1. Hey there, Lucille,

      Glad you are enjoying the calculator.

      To set her personal usage rates and the suggested usage rates in the EOCalc, Kenna compared gas chromatography reports from several essential oil sources and determined average amounts of components such as cinnamaldehyde (aka cinnamic aldhedyde).

      The max rate for cinnamon leaf essential oil usage is not the same as the IFRA standard for cinnamaldehyde because cinnamaldehyde generally makes up less than 20% of cinnamon leaf essential oil. Here is an example of a GC analysis for cinnamon leaf: http://www.thegoodscentscompany.com/gca/gc1028071.html

      (You could compare essential oils and their components to food. Bacon has a substantial amount of fat (which should be used in moderation) in it, but it is not 100% fat when you look at it’s nutritional breakdown. Each component is part of the whole. Essential oils are the same way.)

      Cinnamon bark oil has a much higher concentration of cinnamaldehyde, which is one reason a lot of soapers opt for cinnamon leaf oil.

      Hope that helps!

  20. Hello mam,
    I’m a beginner in cp soap making. I want to know whether the essential oils should be diluted with any of the carrier oils before using it in soaps?
    Thank u 😊 mam.

  21. This was a great article, very helpful and specific. Thank you for the good content. If possible could le me know if you have any articles on suppliers?

  22. Hi, I would like to use Thyme essential oil in my cold process soap. It contains Borneol: 22.7% – 37.5% and Thymol: 1% – 5%. I cannot find info on using this oil online or on the IFRA website. Any thoughts on an appropriate usage rate or should I avoid it altogether? Thanks!

    1. Hey, Nina,
      You might find it easier to look up the safety for thyme via this site (not sure if you have red or white thyme, so this is just an example), and then confirm with IFRA.

      Robert Tisserand Essential Oil Safety is another excellent reference to have on hand.

      After looking over those resources we found some things to be aware of with common thyme oil constituents:
      -Many thyme EOs have carvacrol. Carvacrol can cause skin irritation, recommended Max dermal use of 1%. The CIR recommends a Max 0.5%
      -Thymol can cause skin irritation, so it’s recommended Max dermal use of 1%. The CIR recommends a Max 0.5%
      -Some thyme also has geraniol which is restricted through IFRA and one of the EU allergens
      -Borneol has no toxicity concerns at this time

      Also, keep in mind that you can support and make suggestions for oil to be added to our EOCalc.com, which make all of this a little easier! (Thyme oil isn’t yet listed.)

      Hope that helps, Nina!

  23. Thank you so much for all of this useful info, i’ve read over it several times trying to take it all in! My question is how do you know what percentage of each oil to use in your E.O. calculator to equal 100%. Is there some sort of magical formula for top, middle and base notes that i’m missing? Or is it just a trial and error sort of thing?

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  25. Hello,

    I understand why you wouldn’t include the water amount as it evaporates during cure but why don’t you include t lye amount?
    I know the lye amount changes based on oils but not by enough that (when you consider some of the water weight will stay) including it will lead to an unsafe amount of FO being used.

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