Essential Oil Dilution Calculator

How it works

Essential oil (mL) = carrier × d ÷ (1 − d) (d = dilution fraction; ≈ carrier × d for small d); drops = mL × drops per mL (≈ 20 for most droppers, 25–30 for thin oils)

Essential oils are concentrated enough to irritate or sensitise skin undiluted, so they are blended into a carrier oil, lotion or butter at a percentage chosen for the person and purpose: 1% for children and daily use, 2% for general adult massage, 3–5% for short-term localised use, and 0.5% or less for the very young, the elderly, pregnancy and the face. A percentage times the carrier volume gives millilitres of essential oil, which most people measure in drops — about 20 per millilitre from a standard orifice reducer, though thin oils like lemon give 25–30 and thick ones like vetiver fewer. Individual oils carry their own dermal maximums, often far below a general 2%, so the most restrictive oil in a blend sets the ceiling; and dilution does not make an oil safe for a child, pet or condition it is unsuited to.

Worked example

A 2% blend in 30 mL of jojoba: 0.6 mL of essential oil, about 12 drops — four each of three oils. The same 2% is 4 drops in a 10 mL roller bottle and 40 drops in a 100 mL massage oil; for a six-year-old you would halve it to 1%.

Frequently asked questions