Essential Oil Dilution Chart (UK): How Much Carrier Oil to Use

Every bottle of essential oil eventually raises the same practical question: how much carrier oil should go with it? Too little, and a blend can feel far stronger on skin than intended. Too much, and you're guessing at a ratio instead of working from one. Get the percentage right once, though, and the same drop count works every time you reach for that size of bottle again.

This is a UK-sized dilution chart: a straightforward drops-to-percentage reference built around the bottle sizes people in the UK actually use for topical blends — 10ml rollers up to 100ml sprays — across the dilution percentages most commonly referenced in aromatherapy guidance, from 0.5% up to 10%. There are no oil-specific claims here about what any blend is "for." It's the maths of dilution, explained plainly, so you can measure a blend with confidence and move on.

The UK essential oil dilution chart

The table below shows how many drops of essential oil to add for a given percentage, across the five container sizes most commonly sold and used in the UK for topical blends.

This chart assumes 20 drops of essential oil per millilitre — the standard approximation used across aromatherapy dilution guidance. It's a practical figure rather than a lab-exact one: drop size varies with the viscosity of the specific oil and the dropper insert fitted to the bottle, so a thin oil through a wide orifice reducer runs a little finer than a thick, resinous oil through a narrow one. Read the counts below as accurate enough to blend from confidently, not as a precise laboratory measurement.

\* Strictly 1.5 drops; rounded up to the nearest whole drop, since half-drops can't be measured in practice.

Count the essential oil drops into the empty bottle first, then top up the rest with your chosen carrier oil to the fill line. Above roughly 50 drops, most people find it quicker to measure the essential oil by millilitre instead of counting individual drops — at 20 drops per ml, that's 60 drops = 3ml, 100 drops = 5ml, and 200 drops = 10ml.

So, how much carrier oil should you use?

Turn the table around and the honest answer is: it depends on where the percentage sits. UK aromatherapy guidance generally places 1–3% as the everyday range for a topical blend on adult skin — the 6–18 drop territory in a 30ml bottle, above. The lower end of the chart (0.5–1%) suits facial skin specifically, since it's thinner and generally more reactive than skin elsewhere on the body, or anyone whose skin is sensitive more generally. The upper end (5–10%) is a genuinely strong concentration — better suited to a small, specific area used for a short period than an all-over daily blend, and always worth patch testing first (more on that below).

One more scope note: this guide covers everyday adult topical use. It isn't a substitute for the separate, more conservative guidance that applies to children, or to anyone pregnant, nursing or under a doctor's care — check age-specific guidance or speak to a pharmacist, midwife or GP first in those situations.

Not every oil needs the same dilution

Percentage is only half the picture — the individual oil matters too. Some oils sit comfortably on skin well up the percentage scale; others are intense enough that most people find them uncomfortable much above 1–2%, regardless of what the chart says. As a rough guide, warming, spice-note oils such as Cinnamon, Clove or Oregano are generally used at the lower end of the scale, while softer, lighter oils such as Lavender or Wild Orange tend to have more headroom before they feel strong on skin. This isn't a judgement about which oil is better — it's simply a difference in how concentrated the natural aroma and constituents are, oil to oil. It's worth researching (or patch testing) the specific oil you're using rather than assuming the same percentage suits all of them equally.

Why dilution matters

Essential oils are concentrated plant extracts — a small bottle represents a meaningful amount of raw plant material, which is exactly why a handful of drops goes a long way. Applied neat, directly onto skin, that concentration sits on a small area all at once. Diluted into a carrier oil first, the same number of drops is spread across a much wider area, at a consistent, repeatable strength every time you use it.

Patch testing is the standard precaution before using any new blend more widely. Apply a small amount of the diluted blend to an inconspicuous area of skin — the inside of the forearm is the usual choice — and leave it for 24–48 hours. If any redness, itching or general discomfort develops, wash the area and don't use that particular blend again. This is worth doing even with a well-diluted blend, since skin sensitivity varies considerably from person to person, and can vary batch to batch even with the same oil.

Carrier oils people commonly use

A carrier oil (sometimes called a base oil) is the neutral oil an essential oil gets diluted into before it goes on skin. Three see the most everyday use in the UK.

Fractionated coconut oil has had its longer-chain fats removed, which is what keeps it liquid at room temperature — ordinary coconut oil solidifies below around 24°C. It's close to odourless, absorbs quickly without leaving much of a residue behind, and resists oxidation well, so an opened bottle keeps for a long time. Our fractionated coconut oil comes in a 115ml bottle.

Jojoba oil is technically a liquid wax rather than a true oil, which is part of why it has an unusually long shelf life without needing added preservatives. It's a little heavier on skin than fractionated coconut oil but still absorbs well, and its molecular structure is often compared to skin's own natural oils — a compositional fact rather than a claim about what it does once applied.

Sweet almond oil has a long history in European aromatherapy and a light, faintly nutty character. It doesn't keep as well as the other two — closer to one to two years once opened, against several years for fractionated coconut oil or jojoba — so it's worth buying a size you'll get through, and storing it away from heat and direct light. As a tree-nut derivative, it's also worth checking against any nut allergy before choosing it over the alternatives.

All three work with every drop count in the table above — the percentage is a ratio of essential oil to total blend, whichever carrier oil makes up the rest.

Roller bottles vs spray bottles

Which container makes sense depends on how the blend will be used. Roller bottles — 10ml and 15ml are the common UK sizes — suit a more concentrated blend applied to a small, specific area, since the rollerball meters out a small, consistent amount each time. Spray bottles — typically 30ml, 50ml or 100ml — suit a lighter application spread over a larger area, such as clothing, room linen or a wider area of skin, since each spray disperses the same total drops much more thinly.

If measuring and mixing your own isn't something you want to do, doTERRA's Touch range is a ready-made alternative: the essential oil is already diluted at the point of manufacture into a 10ml roller applicator, such as Lavender Touch or Frankincense Touch — a straightforward way to try a diluted blend before buying a carrier oil and mixing your own.

FAQ

How many drops of essential oil are in 1ml?

Most guidance, including this chart, works on an assumption of around 20 drops per millilitre. It's an approximation rather than an exact figure — thinner oils through a wider dropper insert tend to produce slightly more, smaller drops per ml, while thicker, more viscous oils produce fewer, larger ones. For everyday blending, the 20-drop figure is accurate enough to work from.

Do I need to dilute essential oil for a diffuser?

No. This chart is for topical use — applying oil to skin. A diffuser disperses drops into the air along with water, which is a different kind of use with its own drop guidance based on tank size, not a skin-safe percentage.

Can I mix a diluted roller bottle in advance, or should I dilute fresh each time?

Pre-mixing is normal practice — it's the whole reason roller and spray bottles exist. Keep the bottle capped and out of direct sunlight, and expect its shelf life to roughly match whichever carrier oil you used (see above), since the carrier is usually the part that degrades first.

Does the type of carrier oil change the percentage I should use?

No. The percentage is the ratio of essential oil to the total finished blend, whichever carrier oil makes up the rest of it. Fractionated coconut oil, jojoba and sweet almond oil are interchangeable in the table above — choose between them based on texture and shelf life, not the maths.

Is a higher percentage always a stronger blend?

In terms of concentration, yes — a 10% blend contains ten times as much essential oil relative to the carrier as a 1% blend of the same size. How strong that feels on skin also depends on the specific oil, though (see "not every oil needs the same dilution," above), so two blends at an identical percentage but with different oils won't necessarily feel equally strong.

Is this chart suitable for use on children?

No — this guide covers everyday adult topical use only. Children need lower percentages than adults, and the right figure varies by age, so check age-specific guidance first, and speak to a pharmacist or GP if you're at all unsure.

The short version

A dilution chart only needs to be right once — after that, it's the same drop count every time you pick up that size of bottle. Work out the percentage you need, count the drops from the table above, top up with a carrier oil that suits the shelf life you want, and patch test anything new before using it more widely. Between our fractionated coconut oil and a roller or spray bottle in the right size, that covers everything you need to measure a blend properly.