Reference
Essential-oil dilution chart
This page does one thing: it lays the dilution arithmetic flat. The only conversion on this site is 1 ml ≈ 20 drops, and every drop figure anywhere — including the matrix on each monograph — is derived from it.
The chart
| Carrier oil | 0.5% | 1% | 2% | 3% |
|---|---|---|---|---|
| 10 ml | 1 | 2 | 4 | 6 |
| 30 ml | 3 | 6 | 12 | 18 |
| 50 ml | 5 | 10 | 20 | 30 |
Pregnancy, children under 6, and rooms with cats or dogs — read the matching contraindication row before you blend.
What each concentration is for
| Strength | Use | Audience |
|---|---|---|
| 0.5% | Facial blends, sensitive or broken skin, children 6-15, first patch test | Adults 16+, intact skin, no pregnancy, no oral medication |
| 1% | Everyday adult body and massage blends, daily leave-on use | Adults 16+, intact skin, no pregnancy, no oral medication |
| 2% | Short-term localised adult use, 7 to 10 days then re-assess | Adults 16+, intact skin, no pregnancy, no oral medication |
| 3% | Adult ceiling for robust oils, small area, short course only | Adults 16+, intact skin, no pregnancy, no oral medication |
Which column applies to whom
| Audience | Definition |
|---|---|
| Adult | Adults 16+, intact skin, no pregnancy, no oral medication |
| Child 6+ | Children aged 6 to 15, single-site use, 10 ml maximum |
| Pregnancy | Pregnancy and breastfeeding, second and third trimester included |
| Pets | Rooms a cat, dog, bird or reptile lives in |
Six hard ceilings
- Never exceed 3% total essential oil in a leave-on blend, whatever the recipe says.
- Add the drops to the carrier, never the carrier to the drops. Counting into an empty bottle is how 3% becomes 9%.
- Citrus peel oils that are cold-pressed carry furanocoumarins. Keep them at or below 0.5% if the skin will see sun within 12 hours.
- Phototoxic oils never belong on the face, neck, décolletage or the backs of the hands, at any dilution.
- Undiluted essential oil on skin is a chemical burn risk. There is no oil that is safe neat except as a pinpoint on a wart or a cold sore, and that is a clinical decision, not a home one.
- Aromatherapy here is informational. It is not medical advice and it is not a treatment for any condition.
Per-oil adult ceilings
The same data ordered from the lowest ceiling upward. The 1% oils come first: they are not the weakest materials, they are the ones with the narrowest margin.
| Oil | Family | Chemotype | Ceiling | Per 10 ml | Pregnancy | Pets |
|---|---|---|---|---|---|---|
| Citrus bergamia | Rutaceae | Limonene / linalyl acetate; bergapten content drives the FCF question | 1% | 2 | caution | avoid |
| Syzygium aromaticum | Myrtaceae | Eugenol-dominant | 1% | 2 | avoid | avoid |
| Cananga odorata forma genuina | Annonaceae | Benzyl acetate / linalool / methyl benzoate, graded I to III | 2% | 4 | caution | caution |
| Chrysopogon zizanioides | Poaceae | Khusimol / vetiselinenol sesquiterpene alcohol type | 2% | 4 | caution | caution |
| Citrus limon | Rutaceae | Limonene-dominant; expressed and distilled differ on furanocoumarins | 2% | 4 | caution | avoid |
| Citrus x paradisi | Rutaceae | Limonene-dominant with nootkatone trace | 2% | 4 | caution | avoid |
| Commiphora myrrha | Burseraceae | Furanosesquiterpene type (furanoeudesma-1,3-diene, curzerene) | 2% | 4 | avoid | caution |
| Foeniculum vulgare var. dulce | Apiaceae | trans-Anethole / fenchone type (dulce = low fenchone) | 2% | 4 | avoid | caution |
| Mentha x piperita | Lamiaceae | Menthol / menthone | 2% | 4 | caution | avoid |
| Origanum vulgare | Lamiaceae | Carvacrol type; CT thymol and CT linalool exist | 2% | 4 | avoid | avoid |
| Piper nigrum | Piperaceae | beta-Caryophyllene / limonene / sabinene type | 2% | 4 | caution | caution |
| Salvia sclarea | Lamiaceae | Linalyl acetate / linalool with sclareol | 2% | 4 | avoid | caution |
| Thymus vulgaris | Lamiaceae | Thymol type (CT thymol); CT linalool and CT thujanol differ | 2% | 4 | avoid | avoid |
| Boswellia sacra | Burseraceae | alpha-Thujene / incensole acetate profile; B. papyrifera differs | 3% | 6 | avoid | caution |
| Cedrus atlantica | Pinaceae | Himachalene / cedrol sesquiterpene profile | 3% | 6 | caution | caution |
| Chamaemelum nobile | Asteraceae | Isobutyl angelate / isoamyl angelate ester type | 3% | 6 | caution | caution |
| Citrus aurantium | Rutaceae | Linalool / linalyl acetate / anthranilate ester type | 3% | 6 | caution | caution |
| Citrus sinensis | Rutaceae | Limonene-dominant; no meaningful chemotype variation | 3% | 6 | caution | caution |
| Coriandrum sativum | Apiaceae | Linalool-dominant (distinct from the leaf oil) | 3% | 6 | caution | caution |
| Elettaria cardamomum | Zingiberaceae | 1,8-Cineole / terpinyl acetate type | 3% | 6 | caution | caution |
| Eucalyptus radiata | Myrtaceae | 1,8-Cineole type, low camphor | 3% | 6 | caution | avoid |
| Helichrysum italicum | Asteraceae | Neryl acetate / italidione type | 3% | 6 | caution | caution |
| Juniperus communis | Cupressaceae | alpha-Pinene / sabinene type | 3% | 6 | avoid | caution |
| Lavandula angustifolia | Lamiaceae | Linalool / linalyl acetate | 3% | 6 | caution | caution |
| Melaleuca alternifolia | Myrtaceae | Terpinen-4-ol type (ISO 4730) | 3% | 6 | caution | avoid |
| Mentha spicata | Lamiaceae | Carvone-dominant | 3% | 6 | caution | avoid |
| Pelargonium graveolens | Geraniaceae | Citronellol / geraniol type | 3% | 6 | caution | caution |
| Pinus sylvestris | Pinaceae | alpha-Pinene / carene type | 3% | 6 | caution | caution |
| Pogostemon cablin | Lamiaceae | Patchoulol / alpha-bulnesene sesquiterpene type | 3% | 6 | caution | caution |
| Salvia rosmarinus (formerly Rosmarinus officinalis) | Lamiaceae | 1,8-Cineole type (CT cineole); CT camphor and CT verbenone differ | 3% | 6 | avoid | avoid |
| Santalum album | Santalaceae | alpha-Santalol / beta-santalol sesquiterpene alcohol type | 3% | 6 | caution | caution |
| Zingiber officinale | Zingiberaceae | Zingiberene / sesquiphellandrene type | 3% | 6 | caution | caution |