Essential Oil Dilution: Advanced – Diluting Pre-Made Blends


EO Dilution Calculator



Hey lovely people! I’ve built a dilution calculator for you! I’ve recently discovered that it’s not as easy as it might seem to dilute essential oils. Why? Because some oils are produced as “blends”, essentially pre-diluted oils. This is fantastic if the blend is created with the dilution you want! But what if it isn’t? What if the bottle in your hand is 20% lavender EO, and 80% fractionated coconut oil, but you’re using it for a child and want a 5% blend? What now, huh?

I ran into this question on an internet forum. Luckily, I had enough chemistry in high school and college to know what I’d need to do. A quick check to make sure I was using the right formula, and I was all good. (One of the comments read, “Treat it as a 100% oil anyway”. Don’t do this! I ran the calculations, and it’s a big difference in some cases!)


Click Here to Learn About How to Dilute Oils, and Why You Should


But what about normal people? Those not inclined to locate their old textbooks? Those not interested in knowing you need to use C1V1=C2V2? I decided to make a chart. To create the chart, I built a calculator in the Open Office version of Excel, for my convenience. Then I thought, “Why not just publish the calculator? Duh!”.  Except you can’t. Or, at least, I couldn’t. WordPress is picky about what code they allow on their site, for security, and this wasn’t going to fly.

So I started searching for a calculator-building app, plug-in, or site. After a week of coding errors and working to figure it out on my own, I finally made it function here, for you! For specifics on the math, I’ve added an example below the dilution calculator. To get down and dirty with the formula, check out this video from St. Joseph’s University.


Notes About This Essential Oil Dilution Calculator

  • The specific oils used will alter the exact dilution. There are approximately 20 drops of essential oil per milliliter. More viscous oils will have fewer, larger drops, while lighter oils will have more, smaller drops. This 20-drop conversion is the industry standard.
  • If you wish to use sizes not indicated, it is possible to “extrapolate”. This means that if you wish to make three ounces of a blend, you can use the one-ounce dilution calculator. Just multiply your result by three!
  • You can’t make your oils stronger with this dilution calculator. It will give an answer, but that answer is nonsense. It may also read “Infinity Drops” while you’re working – once you’re finished that will go away. That’s not an answer, it’s a way to blow through your retirement savings!
  • Always add the essential oils to the container first, then follow with carrier oil.

Use This Essential Oil Dilution Calculator

  1. Enter the current percentage of essential oils in your blend, as a decimal. Don’t remember how? It’s OK! Pure essential oil is 100%, and when written as a decimal, that’s the number one (1). Anything lower than 100% will have a decimal. So 99% would be written as “0.99”. And 50% blends would be “0.5”. If you have trouble, this is a fantastic explanation of the process!
  2. Choose the size of your vessel, or the closest one that will work. If you’re making a teaspoon of something, you’ll add the essential oils to the teaspoon, then add carrier oil to the top. If you need to make a tablespoon, that’s three teaspoons – just use the teaspoon option and multiply the answer by three!
  3. Enter your desired outcome, again as a decimal. Remember, some blends get really dilute, like blends intended for small children – so count those zeros! 25%, a very strong blend for short-term topical use, is “0.25”. A 2.5% blend for regular topical adult use is “0.025”. And a common blend for use with young children is 0.25% – written as “0.0025”.
  4. If you get an answer that doesn’t seem to make sense, please let me know in the comments! I’ve worked through a number of possible combinations, and it has worked well. But since I created it, only you can help me make it better!


The Formula

No big secrets here. This is high school chemistry, or it was in Chem II with Mr. Dunfee at Bellaire High School back in 19noneofyourbusiness. The formula is C1V1=C2V2C1 is equal to the concentration of the initial blend, and C2 is the final concentration. V1 is the original volume (in this case, milliliters of essential oil), and V2 is the final volume. Usually used to find the total volume of a solvent needed for making solutions, it was easily adaptable to this purpose.

So, to check the dilution calculator, let’s say you have a blend that is bottled at 20% essential oil, and 80% FCO. You want to create a 10ml roller ball blend that is 2% essential oil, and 98% FCO. What would you do?


Set it Up

V1= 1ml

Finish It

You need 1 milliliter of your initial blend in your final blend. Using the approximation that there are 20 drops per milliliter, that means you’d add 20 drops of your initial blend to the bottle, then 9ml of carrier oil to “top off” the 10ml total. Using the formula and measuring in milliliters does allow for more accurate blends. It also means you work in very small units and need special equipment to measure them.


Tell Me About It!

Did this calculator help? Did you find a bug? Please comment either way – I’d love to hear from you!


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Essential Oil Dilution Calculator


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