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Essential Oil Dilutions & Conversions Guide

Herbal Oil in a Amber Bottle

Have you ever been happily crafting herbal treats with your favorite essential oils and suddenly realized there are different units of measurement to convert from drops to ounces to milliliters? Does this lead you down the inevitable path to a math-induced headache? Well, here are a few tips to keep in mind when it comes to converting ounces to milliliters to drops and diluting essential oils with ease.

Essential Oil Conversions

Ounces -> Millileters

Ounces Millileters
1/8th oz 3.75 ml
1/4th oz  7.5 ml
1/2 oz 15 ml
1 oz  30 ml
4 oz 120 ml
8 oz  237 ml
16 oz  473 ml


Technically, there are 29.57 ml in a 1 oz bottle of essential oil, however, this is usually rounded up to 30 ml on labels and in recipes. This gives you a nice whole number to work with and less agonizing over decimal points.


There are around 20 drops of essential oil in 1 ml.

Ounce -> Drops

Ounces Drops
1/8th oz 75 drops
1/4th oz 150 drops
1/2 oz  300 drops
1 oz  600 drops

See our Essential Oil Blending Tips article for blending basics. These drop conversions will help you multiply any 10-drop blend for the appropriate amount that you need.


Organic Essential Oils In Triangle Formation


Essential Oil Dilutions

Essential oils are very strong and must be diluted (usually in a carrier oil) or incorporated into a finished product such as a massage oil, lotion, or aroma spray. Whether diluting an essential oil or adding it to a finished product, the oil content should only account for 1% to 2% of the total blend.

Here's an easy guide for how much essential oil to add to 1 oz of carrier oil or to a finished product. These dilutions for 1 oz can be easily multiplied for larger batches of finished product or divided for a fraction of an ounce.

Let's use our conversions from above!


1% Dilution

1 oz = 30 ml = 600 drops of oil

1% of 600 drops is 6

Add 6 drops of essential oil for 1 oz of carrier oil or finished product.

2% Dilution

1 oz = 30 ml = 600 drops of oil

2% of 600 drops is 12

Add 12 drops of essential oil for 1 oz of carrier oil or finished product. 


Want to give essential Oil blending a Try?

Check Out Our Essential Oil Blending Tips

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This blog was originally published in 2013. Because it's so popular, we decided to update it for you. Enjoy!  

Topics: Aromatherapy


Written by Christine on August 28, 2017

As Products Manager, Christine Rice has been working with the botanical goodies at Mountain Rose Herbs for over 14 years. With a Certificate in Aromatherapy from The American Collage of Healthcare Sciences she works closely with the essential oils and hydrosols that we offer. She connects with the aromatherapy industry through our National Association of Holistic Aromatherapy business membership and contributes on working committees with The American Herbal Products Association. In addition to her love for aromatics and blending essential oils, Christine can be found gardening and exploring the beautiful Pacific Northwest. She enjoys canning and preserving food, knitting when she has time, and keeps busy with her energetic daughter.