Eau De Cologne, Eau De Toilette and Eau De Parfum reflect the concentration of aromatic compounds in a solvent, which is typically a mix of water and ethanol. The intensity and longevity of a perfume is based on the concentration, intensity and longevity of the aromatic compounds, or perfume oils, used. As the percentage of aromatic compounds increases, so does the intensity and longevity of the scent. The most widespread terms are:
- Eau De Parfum (EDP): 10–20% (typical ~15%) aromatic compounds, sometimes listed as "millésime".
- Eau De Toilette (EDT): 5–15% (typical ~10%) aromatic compounds.
- Eau De Cologne (EDC), often simply called cologne: 3–8% (typical ~5%) aromatic compounds.
- Splashes, Mists and other imprecise terms. Generally these products contain 3% or less aromatic compounds.
Due to the wide range in the percentages of aromatic compounds that may be present in each concentration, the terminology of EDP, EDT, and EDC is quite imprecise. Although an EDP will often be more concentrated than an EDT and in turn an EDC, this is not always the case. Different perfumeries or perfume houses assign different amounts of oils to each of their perfumes. Therefore, although the oil concentration of a perfume in EDP dilution will necessarily be higher than the same perfume in EDT from within a company's same range, the actual amounts vary among perfume houses. An EDT from one house may have a higher concentration of aromatic compounds than an EDP from another.