A Guide to Working Out Measurements

A Guide to Working Out Measurements
When creating preparations, it is necessary to be reasonably accurate in measuring the
ingredients used. Especially with active ingredients like essential oils, you need to know that you are
using enough to be effective, but not too much that an adverse reaction such as skin irritation
could develop.
If you are preparing a relatively large batch of a formula, say 500mL and above, we can suggest:
 Weighing ingredients will always be the most accurate way to measure, battery powered small weighing scales that are accurate to 0.1 gram. Such scales are suitable for most uses. For larger batches, you can contact any laboratory supply company about the weighing scales they offer.
 If measuring ingredients by volume, obtain some accurate measuring beakers and
measuring eye droppers or pipettes. Measuring volume is certainly accurate enough for most
purposes.
If you are making up small batches of a preparation for use on a client, you will find that youcan be reasonably accurate if you measure your essential oils in drops.
However, be warned that not all “drops” are the same! There are a variety of “dropper inserts”
for essential oil bottles in the marketplace. Depending on the size of the aperture, the drop size
can vary widely, from 18 drops to 40 drops per 1mL. Hence, a recipe that calls for 10 drops of
essential oil in 10mL of a vegetable oil can vary from about 5.5% to 2.5% in concentration of
essential oil – quite a difference.
The pharmaceutical drop dispensers that we use for Essential Therapeutics essential oils dispense
on average:
32 drops per 1mL.
Disposable measuring plastic pipettes and standard glass eye droppers also generally give this
approximate drop size.
To work out percentages, a small calculator is very useful. Say you wish to make a 2.5%
concentration of essential oils in 20mL of Essential Base Cream. How many drops of oil
should you add?
With your calculator: 20 (mL of Base Cream) times 2.5 (then press the % key) equals 0.5. This
means 0.5mL of essential oil needs to be added to the cream. There are 32 drops in 1mL, so 32
times 0.5 (mL) equals 16.  16 drops of essential oil are required.
A simple guide:
For a 0.5% concentration of essential oils in a carrier base use:
                   4 drops of essential oil per 25ml of carrier
For 1.0 %: 3 drops of essential oil per 10ml of carrier
For 1.25%: 4 drops of essential oil per 10ml of carrier
For 2.5%: 8 drops of essential oil per 10ml of carrier
For 5%: 17 drops of essential oil per 10ml of carrier
For 10%: 35 drops of essential oil per 10ml of carrier
In terms of the weight of essential oils, at 32 drops being 1mL of oil, each drop weighs
approximately 25 mg (milligrams).

3% Essential Oil Dilutions
We provide some of the more precious, expensive essential oils as a 3% dilution in pure Jojoba
oil. We have been asked “how many drops of the diluted oil should I use to equal the undiluted
essential oil?”
As a 3% dilution, you need to use 33 times as much to equal the undiluted oil. Further, 32
drops or 1mL of the 3% dilution will equal (close enough) 1 drop of undiluted oil. 33 drops
to be exact!
These 3% dilutions are primarily designed to be used ‘as is’ or diluted somewhat to be used
directly on the skin.
Some Useful Volume Measurements…
Amigel Powder 2.5mL – ½ teaspoon = 1.0 gram
Laponite Powder 1.25mL – ¼ teaspoon = 1.3 grams
Superfine Green Clay 5mL – 1 teaspoon = 7 grams
Superfine Pink Clay 5mL – 1 teaspoon = 2.1 grams
Superfine Red Clay 5mL – 1 teaspoon = 4.1 grams
Superfine Yellow Clay 5mL – 1 teaspoon = 5 grams
Superfine White Clay 5mL – 1 teaspoon = 3.2 grams
Emulsifying Wax 15mL – 1 tablespoon = 4.7 grams
Vegetable oils and essential oils –10mL = approximately 9 grams