In short
Terms like eau de parfum and eau de toilette describe how diluted a fragrance is, but they are conventions rather than fixed standards. A maker should think in the actual percentage of concentrate, because that number can be calculated, recorded and repeated, while the label cannot.
What you will learn
- Use the common concentration terms correctly
- Explain why the percentages are conventions and not regulated definitions
- Calculate how much concentrate is in a stated dilution
Before this lesson: Volatility: Why Top, Heart and Base Notes Exist
Concentrate and dilution
The perfumer composes a concentrate. That concentrate is then diluted, usually in perfumer's alcohol, to make the product you spray. All the familiar names describe that last step. They tell you nothing about what the concentrate contains.
The terms, as customary ranges
| Term | Commonly quoted range |
|---|---|
| Parfum or extrait | About 20% and up |
| Eau de parfum (EDP) | About 15 to 20% |
| Eau de toilette (EDT) | About 5 to 15% |
| Eau de cologne (EDC) | About 2 to 5% |
You will find other figures elsewhere, and that is the point. Treat these as rough customs. Two consequences follow for anyone learning to make perfume:
- A label tells you little about performance. A low-percentage fragrance built on powerful materials can be stronger than a high-percentage one built on quiet ones.
- Higher is not simply better. Some compositions become unbalanced at a higher concentration, and regulated materials limit how far you can go in a given product. Level 10 covers those limits.
Choosing between strengths as a buyer is a different question, and the RUŌOD Journal's guide to concentrations answers it.
The only arithmetic you need today
Concentration is the weight of concentrate divided by the total weight, as a percentage:
concentration % = concentrate weight ÷ total weight × 100
For example, 3 g of concentrate in a 20 g total is 3 ÷ 20 × 100 = 15%. To go the other way, 50 g of perfume at 12% holds 50 × 0.12 = 6 g of concentrate and 44 g of solvent. Notice that the total includes the concentrate. A very common beginner mistake is to add 6 g to a full 50 g of alcohol, which gives a weaker result than intended. Our concentration guide goes deeper, including converting between weight and volume for a bottle.
Practical exercise: Work out what is in the bottle
Part one is arithmetic. Work these out on paper before you check the answers.
- You mix 8 g of concentrate with 32 g of alcohol. What is the concentration? Answer: 8 ÷ 40 = 20%.
- You want 30 g of perfume at 10%. How much of each do you weigh? Answer: 3 g of concentrate and 27 g of alcohol.
- A friend says their 100 g batch holds 18 g of concentrate. Which conventional term might fit? Answer: 18% is within the range usually called eau de parfum, though no rule fixes the name.
Part two uses your nose. If you own the same fragrance in two strengths, or one fragrance alongside a lighter body spray, compare them on labeled strips at 1 minute and 1 hour. Write down whether the difference is in strength, in character, or in both.
You have done this well if your samples were labeled and compared at both times, and your conclusion separates a difference in strength from a difference in character.
Common mistakes
- Treating the names as definitions. They are not. Always record the actual percentage.
- Adding concentrate on top of a full solvent amount. The percentage is of the total. Subtract the concentrate from the total first.
- Using volume for the sums. Alcohol is less dense than most concentrates, so percentages by volume and by weight differ. Work by weight, as our guide to weight and volume explains.
Key terms
- Concentrate
- The undiluted fragrance formula, before it is diluted in alcohol or another carrier. Also called the fragrance oil or compound.
- Eau de parfum
- A concentration term, abbreviated EDP, conventionally stronger than eau de toilette. Percentages vary by brand.
- Eau de toilette
- A concentration term, abbreviated EDT, conventionally lighter than eau de parfum. Percentages vary by brand.
Knowledge check
Written and reviewed by the RUŌOD Lab team. This is general education, not legal, regulatory, medical or safety advice. Example dilutions and exercises are for learning, are not validated products, and have not been safety-assessed. Completing a lesson confers no qualification. How we check these lessons.