Blending Factor Calculators

The essential

The blending factor (BF) of an aromatic oil will give an indication of whether you need to put more or less of this oil in a synergy (mixture) in order to create a well-balanced blend.

Blending Calculators

Do you blend essential oils?


If your answer is yes, you have surely noticed that some essential oils are stronger than others. This means that one often has to adjust the number of drops for each oil in order to balance them (olfactively speaking). It is not easy!


In order to help create some guidelines on how to do this, essential oils have been assigned a rank according to the strength of their odor. This ranking of “perfume power” is called the blending factor (BF).


Don’t worry if you have not heard of it before! The use of BF is not common in aromatherapy. Most discussions in aromatherapy center on the therapeutic effects of essential oils due to their specific chemical compositions, but aromatic aspects are often forgotten!


Illustration blog about blending factor approach

1. What is the blending factor in aromatherapy?

2. How to use blendinf factor for essential oisl?

3. Blending factor calculators 

3.1 Blending Calculator - Basic Version
3.2 Blending Calculator - VEP verssion

4. Conclusion

  • FAQ
  • Disclaimer
  • Acknowledgments
  • Pictures

1. What is the blending factor in aromaterapy?

In aromatherapy, the blending factor (BF) is a ranking from 1 to 10 which rates the strength of the odor of essential oil.


Blending factor scale illustration "Less is more"

Picture from Teona Swift

On this scale, 1 is a strong and powerful oil, whereas a 10 is very light and subtle.


2. How to use blending factor for essential oils?

Suppose you mix oil with a BF of 2 with an aromatic oil with a BF of 8.


In that case, you need to add more of the second essential oil or less of the first oil in order for the blend to remain balanced olfactorily (e.g. in order for the perfume of the BF 8 oil not to be overwhelmed by the smell of the oil with a BF of 2).


Picture from Teona Swift

Sometimes "less is more", picture Pixabay

3. Blending calculators

Après-You has created two Blending Calculators to help you to balance your creations quickly and easily. 


3.1 Blending Factor Calculator - Basic Version

This calculator gives you the percentage of each oil for your blend. You can choose up to  three essential oils to blend from a list of nine common oils.


3.2 Interpretation of the results

Once you have sellected the oils you want to blend, you get a graphic telling you the pourcentage of each essential oil you need to balance "olfactively speaking" it.


Down there is an example with Lavender oil, Orange oil and Geranium oil. It helps to understand how to use this calculator.


3.3 Blending Calculator - VEP Version

Après-You’s VEP group can access a dedicated section on Après-You’s website where they find more tools, including an advanced BF calculator as well as various other information for free. 


The VEP Blending calculator is a more precise tool. It allows you to choose from a list of 27 EO, and to simulate the blending of up to five oils.


Additionally, it will also calculate the number of drops you need for each oil to produce the expected volume of the blend. 


Example of blend calculation with BF Calculator - VEP version
Example of blend calculation with BF Calculator - VEP version


Subscribe here to take advantage of Après-You’s great resources and join the VEP group for free! You also benefit from exclusive discounts throughout the year.

3. FAQ

1/ Can I rely on the calculators?

Yes, you can! :) Après-you has done tests, for which the calculators were extremely useful. These calculators are great and simple tools you can use as a foundation for your own mixtures.


Because essential oils are natural products, their odor can be more or less powerful depending on various factors (the brand, their origins, the distillation process, and the year of production…)


For this reason, the percentages or numbers of drops given are informative and may have to be adapted for you to obtain the desired result.


2/ What do I do if the oil I would like to blend does not appear in the calculator?

If you use the Basic version, I recommend you to join the VEP group (it is free and it is here)  in order to see whether you can find the oil in the VEP version of the BF Calculator


If you already use the VEP version, please drop an email–Après-You is continually looking to update Après-You’s offerings and tools!


3/ Can I use these calculators for free?

Yes:) But please be respectful! Après-You has spent a lot of time and effort creating these calculators. If you want to present or use these calculators outside of your private usage, please cite Après-You and include a link to Après-You’s website. Thank you:)


Be safe, be essential!

Very Essential People

You can be part of the VEP group.


You will get informed of the new articles and you will get discounts on the Après-You e-shop, you just have to sign up.


It is free and without engagement.


Après-You cannot be held responsible for any effect of the blends created from this calculator. The calculators are tools and should only be used as a help in your aromatherapy journey.


Do not forget, essential oils are powerful natural products. In most cases, one need only use one’s common sense in making use of essential oils; do not apply in the eyes, ears, or other sensitive areas. Particular care should be taken with children, pregnant or nursing women, and people suffering from allergies or medical conditions.


In case of doubt or extreme practice (like ingestion, which Après-You does not recommend), it is good practice to speak with a medical practitioner or a professional aromatherapist before application.



Après-You wants to thank Sabine for her introduction to the blending factor notion.



If you have any questions or remarks about the pictures and credits, feel free to send an email to info@apres-you.com.

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