Drops · millilitres · percent
Essential oil dilution calculator
How many drops make a 2% body oil in a 30 mL bottle? What percentage did your six drops in 10 mL make? Work it out both ways and compare it with the dilution ranges published by the Tisserand Institute.
- Essential oil12 drops0.6 mL, in a 30 mL bottle
- Carrier29.4 mLfinished blend 30 mL
2% is within the 1–3% range the Tisserand Institute gives for body oils and lotions.
2% in common bottle sizes
| Bottle | Drops | mL |
|---|---|---|
| 5 mL | 2 | 0.1 mL |
| 10 mL | 4 | 0.2 mL |
| 30 mL | 12 | 0.6 mL |
| 50 mL | 20 | 1 mL |
| 100 mL | 40 | 2 mL |
Drops at 20 per mL; real drops vary with the dropper and the oil, so weigh or measure in mL for small or strong batches.
- Dilution2.91%of the finished blend
- Blend10.3 mL0.3 mL oil (6 drops) + 10 mL carrier
| Use | Range | 2.91% is |
|---|---|---|
| Face products and deodorants | 0.2–1.5% | Above |
| Body oils and lotions | 1–3% | Within |
| Bath products | 2–4% | Within |
| Rollerball for a small area of skin | 3–10% | Below |
| Babies under 3 months | 0.1–0.2% | Above |
| Babies 3 to 24 months | 0.25–0.5% | Above |
| Children 2 to 6 years | 1–2% | Above |
| Children 6 to 15 years | 1.5–3% | Within |
Uses from the Tisserand Institute's general dilution guide; ages from its chart after Tisserand & Young (2014). From age 6 the age figures are for whole-body use.
How to use the dilution calculator
Drops for a percentage. Choose what the blend is for and the dilution fills in with the Tisserand Institute's common figure, or type your own. Enter the amount, then say whether it is the finished blend (a 10 mL roller bottle, say) or the carrier you will add the oil to. You get the drops and millilitres of essential oil, the carrier, and a chart for common bottle sizes.
Percentage from drops. Enter the drops (or millilitres) of all your essential oils together and the carrier, and see the percentage beside every published range.
Percentages here are of the finished blend by volume, which is how dilution charts are written. A 2% blend in a 30 mL bottle holds 0.6 mL of essential oil, about 12 drops. If you add 2% to 30 mL of carrier instead, the oil is slightly more, 0.61 mL, because the oil adds to the volume; at these strengths the difference is under a drop.
Worked example
A 10 mL rollerball for a small area at the Institute's common 5% needs 0.5 mL, about 10 drops, topped up with 9.5 mL of carrier. Six drops in 10 mL of carrier is 0.3 mL in 10.3 mL, or 2.9%: inside the 1 to 3% range for body oils and above the 1.5% ceiling for face products.
About drops
Drops are approximate. Viscous oils such as vetiver or sandalwood fall in bigger, slower drops than citrus oils, and droppers differ. For small batches of strong oils, a 1 mL graduated pipette or a 0.01 g scale is more accurate.
Oils with much lower limits
The ranges above suit most essential oils, but some have their own, much lower maximum. Phototoxic oils contain furanocoumarins that can cause burn-like reactions and dark marks when the skin meets sunlight or a tanning bed, for at least 12 hours after application according to the Tisserand Institute. Distilled and furanocoumarin-free (FCF) versions are not phototoxic. If you combine two phototoxic oils, use less of each. The last column updates with the amount in the calculator.
| Oil | Maximum | Most in 30 mL (1.01 fl oz) |
|---|---|---|
| Fig leaf absolute | None | Avoid on skin |
| Lemon verbena oil | None | Avoid on skin |
| Taget (tagetes) oil or absolute | 0.01% | under 1 drop (0 mL) |
| Rue oil | 0.15% | under 1 drop (0.05 mL) |
| Mandarin leaf oil | 0.17% | 1 drop (0.05 mL) |
| Bergamot oil (cold-pressed) | 0.4% | 2 drops (0.12 mL) |
| Cumin oil | 0.4% | 2 drops (0.12 mL) |
| Lime oil (expressed) | 0.7% | 4 drops (0.21 mL) |
| Angelica root oil | 0.8% | 4 drops (0.24 mL) |
| Bitter orange oil (expressed) | 1.25% | 7 drops (0.38 mL) |
| Lemon oil (expressed) | 2% | 12 drops (0.6 mL) |
| Grapefruit oil (expressed) | 4% | 24 drops (1.2 mL) |
| Mandarin fruit oil (expressed) | 5% | 30 drops (1.5 mL) |
Other oils are limited because they irritate or sensitise skin easily rather than because of sunlight. The Tisserand Institute names lemongrass, clove and cinnamon bark as more likely than most to cause reactions, and NAHA lists cassia, cinnamon bark and Peru balsam among the oils it does not recommend for massage. Old, oxidised citrus and pine oils are also more likely to sensitise, so keep oils capped, cool and dark, and replace them when they smell stale.
Safety notes
- Never use essential oils undiluted on skin, and never drip them into eyes or ears.
- Baths: oils float on water in undiluted droplets, so mix them into a suitable dispersant or bath base first. NAHA advises keeping bay, clove, cinnamon bark, lemongrass and thyme (thymol type) out of baths altogether.
- Children: use the lower age-based ranges, and ask a doctor before using any essential oil on a baby. NAHA urges special caution with wintergreen and birch, eucalyptus and peppermint around children. Store bottles where children cannot reach them.
- Pets: some essential oils are harmful to cats and dogs if licked or swallowed. Keep blends and diffusers away from them, and call a vet if a pet is exposed.
- Patch test each new blend on a small spot for several days, and stop if the skin reacts. If you are pregnant, breastfeeding, have a skin condition, asthma or epilepsy, or take medicine, ask a doctor or pharmacist first. Never swallow essential oils.
Questions
How many drops of essential oil for a 2% blend in 10 mL?
2% of a 10 mL bottle is 0.2 mL of essential oil, about 4 drops at 20 drops per mL. In a 30 mL bottle it is 0.6 mL, about 12 drops, and in 1 US fl oz (29.6 mL) also about 12 drops.
What dilution should I use on my face?
The Tisserand Institute's general guide gives 0.2 to 1.5% for facial products and deodorants, with 1% as a common choice. Facial skin is thinner and more reactive, so start low and patch test.
Why do dilution charts disagree by a drop or two?
Some charts take a percentage of the carrier alone and others of the finished blend, and they assume different drop sizes. At everyday strengths the difference is less than a drop; the drop size of your own dropper matters more.
Can I use essential oils on children?
The Tisserand Institute's age chart gives much lower ranges for children, from 0.1 to 0.2% for babies under 3 months up to 1.5 to 3% for ages 6 to 15. Ask a doctor first, especially for babies, and avoid oils singled out for children such as peppermint and eucalyptus.
Is a stronger dilution more effective?
This calculator makes no claims about what oils do. What is well documented is that the risk of irritation and allergy rises with concentration, so the published ranges stay low for products used often or over large areas.
Sources
- Tisserand Institute, How to use essential oils safely: the general dilution guide (2022: face products and deodorants 0.2–1.5%, body oils and lotions 1–3%, bath products 2–4%, rollerballs 3–10%), the age chart (0–3 months 0.1–0.2%, 3–24 months 0.25–0.5%, 2–6 years 1–2%, 6–15 years 1.5–3%), and advice on baths, eyes, ingestion and flammability.
- Tisserand Institute, Phototoxicity: essential oils, sun and safety (2023), Table 2: phototoxic oils and their maximum levels.
- Robert Tisserand and Rodney Young, Essential Oil Safety, 2nd edition, Churchill Livingstone Elsevier, 2014: the source of the age-based dilutions and phototoxic limits.
- National Association for Holistic Aromatherapy (NAHA), Safety information: most blends between 1 and 5%, dermal irritants and sensitisers, oils to keep out of baths, cautions for children.
- American Academy of Dermatology, How to test skin care products.